function empty(x)
{
	return x == '';
}

function validateLoginForm()
{
	$error_count = 0;
	
	if(empty(document.getElementById('user_name').value))
	{		
		document.getElementById('username_label').className = 'label_error';
		document.getElementById('user_name').className = 'textinput_error';
		$error_count++;		
	}
	else
	{		
		document.getElementById('username_label').className = 'label';
		document.getElementById('user_name').className = 'textinput';
	}	

	if(empty(document.getElementById('password').value))
	{		
		document.getElementById('password_label').className = 'label_error';
		document.getElementById('password').className = 'textinput_error';
		$error_count++;		
	}
	else
	{		
		document.getElementById('password_label').className = 'label';
		document.getElementById('password').className = 'textinput';
	}	

	if($error_count > 0)
	{
		alert('You have  left one or more of the form fields blank.\n Please make the necessary corrections before continuing.');	

	}
	else
	{
		document.getElementById('loginForm').submit();	
	}
	
}