Domain name validation using javascript | Learning Curve- Perfect Tutorial for the beginers

Following are the code for domain name validation.

<!DOCTYPE html>
<html>
<body>

<h1>Web Url Validation</h1>

<input type='text' name='Website' id='Website'>
<button id="mybutton" onclick="myFunction()">Validate</button>
<p style="color:red" id="error"></p>
<script>
function myFunction()
{
    var text = document.getElementById("Website").value;
	
    var pattern = /^(http[s]?:\/\/){0,1}(www\.){0,1}[a-zA-Z0-9\.\-]+\.[a-zA-Z]{2,5}[\.]{0,1}/;
         
    if (!pattern.test(text))
    {

	document.getElementById("error").innerHTML = "Invalid domain";
		        
    }
    else
    {

    document.getElementById("error").innerHTML = "Valid domain";
    }
}
</script>
</body>
</html>

<!DOCTYPE html>

<html>

<body>

<h1>Web Url Validation</h1>

<button id="mybutton" onclick="myFunction()">Validate</button>

function myFunction()

{

var text = document.getElementById("Website").value;

var pattern = /^(http[s]?:\/\/){0,1}(www\.){0,1}[a-zA-Z0-9\.\-]+\.[a-zA-Z]{2,5}[\.]{0,1}/;

if (!pattern.test(text))

{

document.getElementById("error").innerHTML = "Invalid domain";

}

else

{

document.getElementById("error").innerHTML = "Valid domain";

}

</script>

</body>

</html>