GlideAjax returns null value

[imran rasheed]

 userMatches - Validates whether the user matches any of the user criteria's listed in the array and returns a boolean value ie true or false 

var userCriterias = ['6b6df061ff2121009b20ffffffffff44','0b5b0e6453631300afffddeeff7b1201'];
var userMatches = sn_uc.UserCriteriaLoader.userMatches(gs.getUserID(), userCriterias);
gs.info(userMatches);

Trying to implement this validation in a catalog to check if the user has met the user criteria for which I am using an onload script to retrieve the userID and passing it to server side script through glideajax. Which returns back null value all the time. Have put on logs to see if the right values are passed on, which seems to be good. Let me know if any changes to be made with the code.
Client script:

function onChange(control, oldValue, newValue, isLoading) {

   if (isLoading || newValue == '') {

      return;

   }

   if(newValue !='')

   {

// Get the current user's ID

    var userID = g_form.getValue('requested_for');

    // Define the user criteria

    var userCriterias = 'b4b142379303311083a1b61efaba1045';

    // Make a GlideAjax call to validate user criteria on the server side

    var ga = new GlideAjax('UserCriteriaValidator');

    ga.addParam('sysparm_name', 'checkUserMatches');

    ga.addParam('sysparm_userCriterias', userCriterias); // Convert to JSON string

    ga.addParam('sysparm_userID', userID);

    ga.getXML(callBack);

    function callBack(response) {

        var answer = response.responseXML.documentElement.getAttribute("answer");

        alert("Answer is " +answer);

   }

}

}

Script include:

var UserCriteriaValidator = Class.create();

UserCriteriaValidator.prototype = Object.extendsObject(AbstractAjaxProcessor, {

    initialize: function() {

    },

checkUserMatches: function () {

      var userID = this.getParameter('sysparm_userID');

      var userCriterias = this.getParameter('sysparm_userCriterias');

      // Check if the user matches the given criteria

      var check = sn_uc.UserCriteriaLoader.userMatches(userID, userCriterias);

      // Return the result

      return check;

   },

   type: 'UserCriteriaValidator'

});

[imran rasheed]

Passed values this way it worked. 🙂

 var userCriterias = [];
        userCriterias.push(this.getParameter('sysparm_userCriterias'));
      // Check if the user matches the given criteria
      var check = sn_uc.UserCriteriaLoader.userMatches(userID, userCriterias);
      // Return the result
     return check.toString();