function checkMail(email)
{
	var x = email;
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if(filter.test(x))
	{
		return true;
	}
	else
	{
		return false;
	}
}