function ajax_check_availability()
{
	var email	=	$('#email').val();

	$("#user_check").html('');
	var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;

	if(reg.test(email))
	{
		$("#user_check").html('<img src="images/ajax_load.gif">');

		$.ajax({
		type: "GET",
		url: "ajax/username_check.php",
		data: "email=" + email,
		success: function(html){
			$("#user_check").html(html);
		}
		});

	}else
	{
		alert('Enter correct email');		
	}
}