Category Archives: PHP

Compare two text file using php

Step1: Create two files named file1.txt and file2.txt with the following contents Apple Orange Mango Pineapple Jackfruit Step2: use the below php file to compare the two text file

<?php
$first_file_data=file_get_contents('file1.txt');
$first_data_line_by_line = explode("\n", $first_file_data);

$second_file_data=file_get_contents('file2.txt');
$second_data_line_by_line = explode("\n", $second_file_data);

  $size_one=count($first_data_line_by_line);
  $size_two=count($second_data_line_by_line);
 $status=true;
 if($size_one!=$size_two)
 {
 
  echo "Files are not Equal";
  
 }
 
 else
 {
$i=0;
foreach($first_data_line_by_line as $val)
{


if($val!=$second_data_line_by_line[$i])
{
$status=false;
break;
}
$i++;
}

if($status==true){echo "Files are  Equal";}else{echo "Files are not Equal";}
}

?>

<?php

$first_file_data=file_get_contents('file1.txt');

$first_data_line_by_line = explode("\n", $first_file_data);

$second_file_data=file_get_contents('file2.txt');

$second_data_line_by_line = explode("\n", $second_file_data);

$size_one=count($first_data_line_by_line);

$size_two=count($second_data_line_by_line);

$status=true;

if($size_one!=$size_two)

{

echo "Files are not Equal";

}

else

{

$i=0;

foreach($first_data_line_by_line as $val)

{

if($val!=$second_data_line_by_line[$i])

{

$status=false;

break;

}

$i++;

}

if($status==true){echo "Files are Equal";}else{echo "Files are not Equal";}

}

Creating dropdown box using php.Dynamic dropdown box using php

Steps: create a database ‘test’. create a table inside test using the below code.

CREATE TABLE IF NOT EXISTS `tbl_city` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `city_name` varchar(255) NOT NULL,
  `state_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=51 ;

--
-- Dumping data for table `tbl_city`
--

INSERT INTO `tbl_city` (`id`, `city_name`, `state_id`) VALUES
(1, 'Kolkata', 1),
(2, 'Asansol', 1),
(3, 'Siliguri', 1),
(4, 'Durgapur', 1),
(5, 'Bardhaman', 1),
(6, 'Dankuni', 1),
(7, 'Ajmer', 2),
(8, 'Bikaner', 2),
(9, 'Jaipur', 2),
(10, 'Udaipur', 2),
(11, 'Shimla', 3),
(12, 'Mumbai ', 4),
(13, 'Pune', 4),
(14, 'Nagpur', 4),
(15, 'Thane', 4),
(16, 'Solapur', 4),
(17, 'Bhiwandi', 4),
(18, 'Amravati', 4),
(19, 'Nashik', 4),
(20, 'Melbourne', 5),
(21, 'Geelong', 5),
(22, 'Kalgoorlie', 6),
(23, 'Rockingham', 6),
(24, 'Bundaberg', 7),
(25, 'Caloundra', 7),
(26, 'Townsville', 7),
(27, 'Mount Isa', 7),
(28, 'Mount Barker', 8),
(29, 'Victor Harbor', 8),
(30, 'Hobart ', 10),
(31, 'Launceston', 10),
(32, 'Sitka', 11),
(33, 'Juneau', 11),
(34, 'Wrangell', 11),
(35, 'Anchorage', 11),
(36, 'Los Angeles', 12),
(37, 'San Diego', 12),
(38, 'New York City', 13),
(39, 'Rome', 13),
(40, 'North Port', 14),
(41, 'Jacksonville', 14),
(42, 'Bunnell', 14),
(43, 'Tampa', 14),
(44, 'Beaumont', 15),
(45, 'Waco', 15),
(46, 'Marana', 16),
(47, 'Eloy', 16),
(48, 'Cleveland', 17),
(49, 'Cincinnati', 17),
(50, 'Jackson', 18);

CREATE TABLE IF NOT EXISTS `tbl_city` (

`id` int(11) NOT NULL AUTO_INCREMENT,

`city_name` varchar(255) NOT NULL,

`state_id` int(11) NOT NULL,

PRIMARY KEY (`id`)

) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=51 ;

-- Dumping data for table `tbl_city`

INSERT INTO `tbl_city` (`id`, `city_name`, `state_id`) VALUES

(1, 'Kolkata', 1),

(2, 'Asansol', 1),

(3, 'Siliguri', 1),

(4, 'Durgapur', 1),

(5, 'Bardhaman', 1),

(6, 'Dankuni', 1),

(7, 'Ajmer', 2),

(8, 'Bikaner', 2),

(9, 'Jaipur', 2),

(10, 'Udaipur', 2),

(11, 'Shimla', 3),

(12, 'Mumbai ', 4),

(13, 'Pune', 4),

(14, 'Nagpur', 4),

(15, 'Thane', 4),

(16, 'Solapur', 4),

(17, 'Bhiwandi', 4),

(18, 'Amravati', 4),

(19, 'Nashik', 4),

(20, 'Melbourne', 5),

(21, 'Geelong', 5),

(22, 'Kalgoorlie', 6),

(23, 'Rockingham', 6),

(24, 'Bundaberg', 7),

(25, 'Caloundra', 7),

(26, 'Townsville', 7),

(27, 'Mount Isa', 7),

(28, 'Mount Barker', 8),

(29, 'Victor Harbor', 8),

(30, 'Hobart ', 10),

(31, 'Launceston', 10),

(32, 'Sitka', 11),

(33, 'Juneau', 11),

(34, 'Wrangell', 11),

(35, 'Anchorage', 11),

(36, 'Los Angeles', 12),

(37, 'San Diego', 12),

(38, 'New York City', 13),

(39, 'Rome', 13),

(40, 'North Port', 14),

(41, 'Jacksonville', 14),

(42, 'Bunnell', 14),

(43, 'Tampa', 14),

(44, 'Beaumont', 15),

(45, 'Waco', 15),

(46, 'Marana', 16),

(47, 'Eloy', 16),

(48, 'Cleveland', 17),

(49, 'Cincinnati', 17),

(50, 'Jackson', 18);

use the below php file that will show a drop down box for you

<?php
// database connection
$linkfirst = mysql_connect('localhost', 'root', '');
if (!$linkfirst) {
    die('Could not connect: ' . mysql_error());
	}
 mysql_select_db('test', $linkfirst) or die('Could not select database.');

//query for selecting user information 
$query = "SELECT * FROM tbl_city";
$results = mysql_query($query,$linkfirst)  or die(mysql_error());
echo '<select name="firstdrop">
      <option value="" disabled="disabled" selected="selected">choose one</option>';
	  
	  
	  while($tier=mysql_fetch_array($results))
	  {
	  
	  echo '<option value="'.$tier['city_name'].'">'.$tier['city_name'].'</option>';
	  
	  
	  }

 echo '</select';
?>

<?php

// database connection

$linkfirst = mysql_connect('localhost', 'root', '');

if (!$linkfirst) {

die('Could not connect: ' . mysql_error());

}

mysql_select_db('test', $linkfirst) or die('Could not select database.');

//query for selecting user information

$query = "SELECT * FROM tbl_city";

$results = mysql_query($query,$linkfirst) or die(mysql_error());

echo '<select name="firstdrop">

<option value="" disabled="disabled" selected="selected">choose one</option>';

while($tier=mysql_fetch_array($results))

{

echo '<option value="'.$tier['city_name'].'">'.$tier['city_name'].'</option>';

}

echo '</select';

File upload using php

step1: create a database ‘test’ and create table inside this database using the following query

CREATE TABLE IF NOT EXISTS `categories` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `ttiles` varchar(250) NOT NULL,
  `path` varchar(250) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

CREATE TABLE IF NOT EXISTS `categories` (

`id` int(11) NOT NULL AUTO_INCREMENT,

`ttiles` varchar(250) NOT NULL,

`path` varchar(250) NOT NULL,

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

step2: create a folder called “fileupload” . step3: .create a folder ‘myfolder’ inside the ‘fileupload’ folder. step4: save the file ‘categories.php’ inside the ‘fileupload’ folder.

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>File upload using PHP:</title>
</head>
<body>

<table align="center">
<tbody>
<tr><td>
<form action="succescategories.php" method="POST" enctype="multipart/form-data">

Title:
<input type="text" name="titles" >
<br><br>
Imagine1:
<input type="file" name="filep" >
<br><br>
<input type="submit" value="Submit">
</form>
</tr></td>
</tbody>
</table>
</body>
</html>

<!DOCTYPE html>

<html>

<head>

<title>File upload using PHP:</title>

</head>

<body>

<tbody>

Title:

Imagine1:

</form>

</tr></td>

</tbody>

</table>

</body>

</html>

step5: save the file ‘successcategories.php ‘ inside the ‘fileupload’ folder.

<?php
$link = mysqli_connect("localhost", "root", "", "test");
 
// Check connection
if($link === false){
    die("ERROR: Could not connect. " . mysqli_connect_error());
}
 
// Escape user inputs for security

$titles = mysqli_real_escape_string($link, $_POST['titles']);


/*to upload fie*/

$fileName = $_FILES["filep"]["name"]; 
$fileTmpLoc = $_FILES["filep"]["tmp_name"];

$pathAndName = "myfolder/".$fileName;

$moveResult = move_uploaded_file($fileTmpLoc, $pathAndName);
// Evaluate the value returned from the function if needed
if ($moveResult == true) {

$insertpath=$pathAndName;
    
} else {
     $insertpath="Error in fie upload";
}




 
// attempt insert query execution
$sql = "INSERT INTO categories (ttiles,path) VALUES ('$titles','$insertpath')";
if(mysqli_query($link, $sql)){
    echo "<h1>Records added successfully.</h1>";
} else{
    echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}
 

 
// close connection
mysqli_close($link);


?>

<p><a href="categories.php">Add Category</a></p>

<?php

$link = mysqli_connect("localhost", "root", "", "test");

// Check connection

if($link === false){

die("ERROR: Could not connect. " . mysqli_connect_error());

}

// Escape user inputs for security

$titles = mysqli_real_escape_string($link, $_POST['titles']);

/*to upload fie*/

$fileName = $_FILES["filep"]["name"];

$fileTmpLoc = $_FILES["filep"]["tmp_name"];

$pathAndName = "myfolder/".$fileName;

$moveResult = move_uploaded_file($fileTmpLoc, $pathAndName);

// Evaluate the value returned from the function if needed

if ($moveResult == true) {

$insertpath=$pathAndName;

} else {

$insertpath="Error in fie upload";

}

// attempt insert query execution

$sql = "INSERT INTO categories (ttiles,path) VALUES ('$titles','$insertpath')";

if(mysqli_query($link, $sql)){

echo "<h1>Records added successfully.</h1>";

} else{

echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);

}

// close connection

mysqli_close($link);

<p><a href="categories.php">Add Category</a></p>

step6: execute… Read More »

How to check a radio button using database content

Create a simple php page that loads the list of users information with name and sex.if value exist in the database with ‘1’ as Male and ‘0’ as Female. Please follow the following steps Step1: create a database called “test”. create a table called “tbl_user_information” using the below query

CREATE TABLE IF NOT EXISTS `tbl_user_information` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(250) NOT NULL,
  `sex` tinyint(2) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;

--
-- Dumping data for table `tbl_user_information`
--

INSERT INTO `tbl_user_information` (`id`, `name`, `sex`) VALUES
(1, 'vasanthan', 1),
(2, 'sudhina', 0);

CREATE TABLE IF NOT EXISTS `tbl_user_information` (

`id` int(11) NOT NULL AUTO_INCREMENT,

`name` varchar(250) NOT NULL,

`sex` tinyint(2) NOT NULL,

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;

-- Dumping data for table `tbl_user_information`

INSERT INTO `tbl_user_information` (`id`, `name`, `sex`) VALUES

(1, 'vasanthan', 1),

(2, 'sudhina', 0);

Step 2: create file called… Read More »

Replace a line of code in a php file using php

Replace a line of code in a php file using php To replace the below line of code in the testreplace.php define(‘PATH_CURRENT_SITE’, ‘/mydoubts/’); this should be changing to define(‘PATH_CURRENT_SITE’, ‘/vasanthan/’); For this please execute the stringreplace.php… changes will reflect in the testreplace.php #File-stringreplace.php

<?php

$newstring="vasanthan";
$mystring="define('PATH_CURRENT_SITE', '/mydoubts/');";
$toFind = "/";
$start = 0;
$firstpos = strpos($mystring,$toFind,$start);
$start_pos=$firstpos+1;
$start=$firstpos+1;
$secondpos=strpos($mystring,$toFind,$start);
$end_pos=$secondpos-1;
$length=$end_pos-$start_pos+1;
$convertedstring=substr_replace($mystring,$newstring,$start_pos,$length);


$Filename_to_change = 'testreplace.php';
$new_string = $convertedstring;
$string_to_replace	=	$mystring;

 

    if(file_exists($Filename_to_change)) {
 
        $File_content = file_get_contents($Filename_to_change);
 
        // Replace the text
        $Value_after_replace = str_replace($string_to_replace, $new_string, $File_content);
 
        // Open the file
        $File_open_for_write = fopen($Filename_to_change, 'w+');
 
        // Write the text into it
        $File_write = fwrite($File_open_for_write, $Value_after_replace);
 
        if($File_write) {
 
            // If success, close file and return true
            fclose($File_open_for_write);
            return true;
 
        }
 
        // If failure, close file and return false
        fclose($File_open_for_write);
        return false;
 
    }
 
    else {
 
        die('File' . $Filename_to_change . 'does not exist!');
 
    }


?>

<?php

$newstring="vasanthan";

$mystring="define('PATH_CURRENT_SITE', '/mydoubts/');";

$toFind = "/";

$start = 0;

$firstpos = strpos($mystring,$toFind,$start);

$start_pos=$firstpos+1;

$start=$firstpos+1;

$secondpos=strpos($mystring,$toFind,$start);

$end_pos=$secondpos-1;

$length=$end_pos-$start_pos+1;

$convertedstring=substr_replace($mystring,$newstring,$start_pos,$length);

$Filename_to_change = 'testreplace.php';

$new_string = $convertedstring;

$string_to_replace = $mystring;

if(file_exists($Filename_to_change)) {

$File_content = file_get_contents($Filename_to_change);

// Replace the text

$Value_after_replace = str_replace($string_to_replace, $new_string, $File_content);

// Open the file

$File_open_for_write = fopen($Filename_to_change, 'w+');

// Write the text into it

$File_write = fwrite($File_open_for_write, $Value_after_replace);

if($File_write) {

// If success, close file and return true

fclose($File_open_for_write);

return true;

}

// If failure, close file and return false

fclose($File_open_for_write);

return false;

}

else {

die('File' . $Filename_to_change . 'does not exist!');

}

2.#File-testreplace.php

<?php
define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', false);
define('DOMAIN_CURRENT_SITE', 'mydoubts.in');
define('PATH_CURRENT_SITE', '/mydoubts/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1); 
?>

<?php

define('MULTISITE', true);

define('SUBDOMAIN_INSTALL', false);

define('DOMAIN_CURRENT_SITE', 'mydoubts.in');

define('PATH_CURRENT_SITE', '/mydoubts/');

define('SITE_ID_CURRENT_SITE', 1);

define('BLOG_ID_CURRENT_SITE', 1);

Find out the largest and smallest value in an array without using array function: using loop

$myArray=array(4,5,88,43,7,100,1);
$lengthofarray=count($myArray);

$guess_largest=0;
$guess_smallest=$myArray[0];


for($i=0;$i< $lengthofarray;$i++)
{
if($myArray[$i]>$guess_largest)
$guess_largest=$myArray[$i];
if($myArray[$i]<$guess_smallest)
$guess_smallest=$myArray[$i];
}
echo "Largest value: ".$guess_largest;
echo "<br>";
echo "Smallest Value: ".$guess_smallest;

//ouput as below

//Largest value: 100
//Smallest Value: 1

$myArray=array(4,5,88,43,7,100,1);

$lengthofarray=count($myArray);

$guess_largest=0;

$guess_smallest=$myArray[0];

for($i=0;$i< $lengthofarray;$i++)

{

if($myArray[$i]>$guess_largest)

$guess_largest=$myArray[$i];

if($myArray[$i]<$guess_smallest)

$guess_smallest=$myArray[$i];

}

echo "Largest value: ".$guess_largest;

echo "<br>";

echo "Smallest Value: ".$guess_smallest;

//ouput as below

//Largest value: 100

//Smallest Value: 1

Regex validation with examples using php

// Validation for characters- it will allow only letters and spaces
//sample entry : hello vasanthan



		        if (!preg_match("/^[a-zA-Z\s]+$/", $name))
				{
				    echo 'Enter characters for Name';
				}

				
//Validation for time-it will validate the time format as hh:mm
//sample entry : 01:09
				 if (!preg_match("/^(([0-1][0-9])|(2[0-3])):[0-5][0-9]$/", $time))
				{
				    echo 'Enter valid format for example hh:mm';
				}
		
				
//valdiation of numbers		
//sample entry : 10  
		     if (!preg_match("/^[1-9]+$/", $hours))
				{
				    echo 'Enter digits as hours';
				}

// Validation for characters- it will allow only letters and spaces

//sample entry : hello vasanthan

if (!preg_match("/^[a-zA-Z\s]+$/", $name))

{

echo 'Enter characters for Name';

}

//Validation for time-it will validate the time format as hh:mm

//sample entry : 01:09

if (!preg_match("/^(([0-1][0-9])|(2[0-3])):[0-5][0-9]$/", $time))

{

echo 'Enter valid format for example hh:mm';

}

//valdiation of numbers

//sample entry : 10

if (!preg_match("/^[1-9]+$/", $hours))

{

echo 'Enter digits as hours';

}

Simple File upload in PHP:storing file names in database

Step1: create a database called testlogin using phpmyadmin. Create a table using the following code execution through phpmyadmin query window

CREATE TABLE IF NOT EXISTS `tbl_file_storage` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `filename` varchar(250) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

CREATE TABLE IF NOT EXISTS `tbl_file_storage` (

`id` int(11) NOT NULL AUTO_INCREMENT,

`filename` varchar(250) NOT NULL,

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

step2: create a folder called ‘fileupload’ and the following files under htdocs folder htdocs – fileupload step3:create a folder ‘storage’ under ‘fileupload’ folder- set permission 777 for storage folder htdocs – fileupload – storage… Read More »

Import Csv file using php and Mysql

Step1: create a database called testlogin through phpmyadmin. execute the below query through phpmyadmin

CREATE TABLE IF NOT EXISTS `tbl_country` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `countryid` int(10) NOT NULL,
  `countryname` varchar(30) NOT NULL,
  `countrycode` varchar(30) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=4

CREATE TABLE IF NOT EXISTS `tbl_country` (

`id` int(10) NOT NULL AUTO_INCREMENT,

`countryid` int(10) NOT NULL,

`countryname` varchar(30) NOT NULL,

`countrycode` varchar(30) NOT NULL,

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=4

use the below files for database connectivity and csv reading and insertion db_connect.php

<?php
$connection_string = mysql_connect('localhost', 'root', '');
if (!$connection_string) {
    die('Could not connect: ' . mysql_error());
}
 mysql_select_db('testlogin', $connection_string) or die('Could not select database.');

?>

<?php

$connection_string = mysql_connect('localhost', 'root', '');

if (!$connection_string) {

die('Could not connect: ' . mysql_error());

}

mysql_select_db('testlogin', $connection_string) or die('Could not select database.');

index.php

<?php
include"db_connect.php";

if (($handle = fopen("country.csv", "r")) !== FALSE) {
$to_avoid_firstline = true;
    while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
	if($to_avoid_firstline) { $to_avoid_firstline = false; continue; }
        $num = count($data);
        $country_id=$data[0];
		$country_name=$data[1];
		$country_code=$data[2];
	    $query="insert into tbl_country(countryid,countryname,countrycode)values('$country_id','$country_name','$country_code')";
		$result=mysql_query($query,$connection_string);
			
        
    }
    fclose($handle);
}
?>

<?php

include"db_connect.php";

if (($handle = fopen("country.csv", "r")) !== FALSE) {

$to_avoid_firstline = true;

while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {

if($to_avoid_firstline) { $to_avoid_firstline = false; continue; }

$num = count($data);

$country_id=$data[0];

$country_name=$data[1];

$country_code=$data[2];

$query="insert into tbl_country(countryid,countryname,countrycode)values('$country_id','$country_name','$country_code')";

$result=mysql_query($query,$connection_string);

}

fclose($handle);

}

Simple login application using php:Login application using php and mysql

Use the following steps create database called ‘testlogin’ and execute the following query

CREATE TABLE IF NOT EXISTS `tbl_login` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `username` varchar(100) NOT NULL,
  `password` varchar(100) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

--
-- Dumping data for table `tbl_login`
--

INSERT INTO `tbl_login` (`id`, `username`, `password`) VALUES
(1, 'admin', 'admin');

CREATE TABLE IF NOT EXISTS `tbl_login` (

`id` int(10) NOT NULL AUTO_INCREMENT,

`username` varchar(100) NOT NULL,

`password` varchar(100) NOT NULL,

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

-- Dumping data for table `tbl_login`

INSERT INTO `tbl_login` (`id`, `username`, `password`) VALUES

(1, 'admin', 'admin');

please save the below files into a folder under htdocs. index.php

<html>
<head>
<title>Simple Login using php-session</title>
<script type="text/javascript">
function validate()

{

if(document.form1.username.value=='')
{
alert("please enter the user name");
document.form1.username.focus();
return false;

}
if(document.form1.password.value=='')
{
alert("please enter the password");
document.form1.password.focus();
return false;
}
return true;

}

</script>
</head>
<body>
<form method="post" action="postdata.php" id="form1" name="form1" autocomplete="off">
 
<table border="1" cellspacing="0" cellpadding="0" align="center" width="350">
<tr>
<td width="1px">User Name:</td>
<td width="1px"><input type="text" name="username" value=""></td>
</tr>
<tr>
<td width="1px">Password</td>
<td width="1px"><input type="password" name="password" value=""></td>
</tr>
<tr>
<td width="1px"></td>
<td width="1px"><input type="Submit" name="Submit" value="Login" onclick="return validate();"></td>
</tr>
<tr>
<td width="1px"></td>
<td width="1px"><div style="text-color=red;"><?php echo @$_GET['msg'];?></div></td>
</tr>
</table> 
</form>
</body></html>

<html>

<head>

<title>Simple Login using php-session</title>

function validate()

{

if(document.form1.username.value=='')

{

alert("please enter the user name");

document.form1.username.focus();

return false;

}

if(document.form1.password.value=='')

{

alert("please enter the password");

document.form1.password.focus();

return false;

}

return true;

}

</script>

</head>

<body>

<tr>

</tr>

<tr>

<td width="1px">Password</td>

</tr>

<tr>

</tr>

<tr>

</tr>

</table>

</form>

</body></html>

database.php

<?php
$connection_string = mysql_connect('localhost', 'root', '');
if (!$connection_string) {
    die('Could not connect: ' . mysql_error());
}
 mysql_select_db('testlogin', $connection_string) or die('Could not select database.');

?>

<?php

$connection_string = mysql_connect('localhost', 'root', '');

if (!$connection_string) {

die('Could not connect: ' . mysql_error());

}

mysql_select_db('testlogin', $connection_string) or die('Could not select database.');

postdata.php

<?php
session_start();
include"database.php";

$user=@$_POST['username'];
$password=@$_POST['password'];
$query="select * from tbl_login where username='$user' and password='$password'";
$sql_result=mysql_query($query,$connection_string);
$num_rows=mysql_num_rows($sql_result);
if($num_rows>0)
{
@$_SESSION['userdetails']=$user;
header("Location:admin.php");
}
else
{
$errormessage="Login failed";
header("Location:index.php?msg=$errormessage");
}
?>

<?php

session_start();

include"database.php";

$user=@$_POST['username'];

$password=@$_POST['password'];

$query="select * from tbl_login where username='$user' and password='$password'";

$sql_result=mysql_query($query,$connection_string);

$num_rows=mysql_num_rows($sql_result);

if($num_rows>0)

{

@$_SESSION['userdetails']=$user;

header("Location:admin.php");

}

else

{

$errormessage="Login failed";

header("Location:index.php?msg=$errormessage");

}

admin.php

<?php
session_start();
if(@$_SESSION['userdetails']=="")
{
header("Location:index.php");
}
?>
<html>
<head>
<title>Simple Login using php and mysql</title>

</head>
<body>

<table border="1" cellspacing="0" cellpadding="0" align="center" width="350">
<tr>
<td width="1px">Welocome : <?php echo $_SESSION['userdetails'];?></td>
<td width="1px"></td>
</tr>
<tr>
<td width="1px"><a href="logout.php">Logout</a></td>
<td width="1px"></td>
</tr>
</table> 
</body></html>

<?php

session_start();

if(@$_SESSION['userdetails']=="")

{

header("Location:index.php");

}

<html>

<head>

<title>Simple Login using php and mysql</title>

</head>

<body>

<tr>

<td width="1px">Welocome : <?php echo $_SESSION['userdetails'];?></td>

</tr>

<tr>

<td width="1px"><a href="logout.php">Logout</a></td>

</tr>

</table>

</body></html>

logout.php

<?php
session_start();
session_destroy();
session_unset();
unset($_SESSION['userdetails']);
header("Location:index.php");
?>

<?php

session_start();

session_destroy();

session_unset();

unset($_SESSION['userdetails']);

header("Location:index.php");