Undefined property: Project::$form_vallidationLearning Curve- Perfect Tutorial for the beginers | Learning Curve- Perfect Tutorial for the beginers

Fatal error: Call to a member function set_rules() on a non-object in error in codeigniter

$this->load->library('form_validation');
		  
		  $this->form_vallidation->set_rules('project_name','Project Name','trim|required|min_lenth[5]|xss_clean');
		
		  if($this->form_validation->run() == FALSE)
		{
			$this->index();
		}

$this->load->library('form_validation');

$this->form_vallidation->set_rules('project_name','Project Name','trim|required|min_lenth[5]|xss_clean');

if($this->form_validation->run() == FALSE)

{

$this->index();

}

Why this error is coming in my coding ?