ChallengeHandler.isCustomResponse and handleChallenge functions are not working in worklight

<script>
    			$(document).ready(function(){
    				alert("Hi");
    			});
    			function getValidate(){
    				alert();
    				var invocationData = {
						adapter : 'Go2needsHTTP',
						procedure : 'getValidate',
						parameters : []
					};
					var options = {
						onSuccess : getValidateSuccess,
						onFailure : getValidateFailure,
						invocationContext: {}
					};
					WL.Client.invokeProcedure(invocationData, options);
    			}
    			function getValidateSuccess(){
    				alert("Success");
    			}
    			function getValidateFailure(){
    				alert("Failure");
    			}
    			var SampleAppRealmChallengeHandler = WL.Client.createChallengeHandler("SampleAppRealm");		
    			sampleAppRealmChallengeHandler.isCustomResponse = function(response) {
    				alert(response);
				    if (!response || response.responseText === null) {
				        return false;
				    }
				    var indicatorIdx = response.responseText.search('j_security_check');
				    
				    if (indicatorIdx >= 0){
						return true;
					}  
					return false;
				}; 
				sampleAppRealmChallengeHandler.handleChallenge = function(response) {
					alert("handleChallenge");
				    $('#AppDiv').hide();
				    $('#AuthDiv').show();
				    $('#AuthPassword').val('');
				};
				$(function(){
					$('#AuthSubmitButton').bind('click', function () {
						alert("AuthSubmitButton");
					    var reqURL = '/j_security_check';
					    var options = {};
					    options.parameters = {
					        j_username : $('#AuthUsername').val(),
					        j_password : $('#AuthPassword').val()
					    };
					    options.headers = {};				    sampleAppRealmChallengeHandler.submitLoginForm(reqURL, options, sampleAppRealmChallengeHandler.submitLoginFormCallback);
					});
				});
				$(function(){
					$('#AuthCancelButton').bind('click', function () {
						alert("AuthCancelButton");
					    sampleAppRealmChallengeHandler.submitFailure();
					    $('#AppDiv').show();
					    $('#AuthDiv').hide();
					});
				});
    		</script>

<div data-role="page" id="page">
    			<div data-role="content" style="padding: 15px">
    				<div id="AppDiv">
						<input type="button" id="getSecretDataButton" value="Call protected adapter proc" onclick="getValidate()" />
						<input type="button" class="appButton" value="Logout" onclick="WL.Client.logout('SampleAppRealm',{onSuccess: WL.Client.reloadApp})" />
						<div id="ResponseDiv"></div>
					</div>
		    		<div id="AuthDiv" style="display: block;">
						<p id="AuthInfo"></p>
						<div id="loginForm">
							<input type="text"`enter code here` id="AuthUsername" placeholder="Enter username" />
							<br/>
							<br/>
							<input type="password" id="AuthPassword" placeholder="Enter password" />
							<br/>
							<input type="button" id="AuthSubmitButton" onclick="WL.Client.Login('SampleAppRealm');" class="formButton" value="Login" />
							<input type="button" id="AuthCancelButton" class="formButton" value="Cancel" />
						</div>
					</div>
    			</div>
    		</div>

<customSecurityTest name="SampleAppRealm-securityTest"> <test realm="SampleAppRealm" isInternalUserID="true"/></customSecurityTest> <loginModule name="StrongDummy" expirationInSeconds="-1"> <className>com.worklight.core.auth.ext.NonValidatingLoginModule</className> </loginModule> <realm name="SampleAppRealm" loginModule="StrongDummy"> <className>com.worklight.core.auth.ext.FormBasedAuthenticator</className> </realm> 

<procedure name="getValidate" securityTest="SampleAppRealm-securityTest"></procedure>