function validate_required(field,alerttxt) {
	with (field) {
	  if (value==null||value=="") {
	    $('err_cell').innerHTML = alerttxt;
	  }else {
	    return true;
	  }
	}
}

function validate() {
	var result = false;
	var username=$("userId");
	var domain=$("domain");
	var password=$("password");
	if(!validate_required(username,"User name is a required field")) {
		username.focus();
		return false;
	}
	if(!validate_required(password,"Password is a required field")) { 
		password.focus();
		return false;
	}
	if (domain.options[domain.selectedIndex].value == "domain") {
		$('err_cell').innerHTML = "Please select domain for your e-mail account";
		domain.focus();
		return false;
	}
	$("submitButton").disabled=true;
	//try ajax request here
	var params = $('loginForm').serialize(true);
	params.action = $("loginForm").action;
	new Ajax.Request('validator.php',
	  {
	    method:'get',
	    parameters: params,
	    onSuccess: function(transport){
	    	$("submitButton").disabled=false;
	      	var response = transport.responseText || "no response text";
					if(response.match("^valid")) {
						$("username").value = $F("userId") + "@" + $F("domain");
						$("loginForm").submit();
					}else {
						$('err_cell').innerHTML = 'Bad user name or password.\nPlease try again.';
					}
	    },
	    onFailure: function(transport,e){ 
	    	$("submitButton").disabled=false;
	    	$('err_cell').innerHTML = 'Server error.\nPlease try again.';
	    }
	  });
	
	return false;
}