//validate email adress
function isValidEmail(email) {
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
   if(reg.test(email) == false) {
	  return false;
   }
   else {
		return true;
   }
}
//validate user form
function validateUserForm()
{
	var ok = true;

	if ($('email').value == '' || !isValidEmail($('email').value)) {
		ok = false;
		$('email').addClass('input-error');			
	}
	else {
		$('email').removeClass('input-error');
		$('email').addClass('input-valid');	
	}
	return ok;
}