How to do Gateway authentication using SAPUI5 mobile app?

Hi,

I am doing mobile application using Net weaver gateway and sapui5 in Phonegap. In that I am passing username and password along with service like below.

var oModel = new sap.ui.model.ODataModel(sServiceUrl, true, "username", "pwd");

Now I want to do authentication before entering into the service.

I followed the below link to do it.

http://scn.sap.com/community/developer-center/front-end/blog/2013/08/02/authentication-to-sap-backend-for-sapui5-hybrid-phonegap-apps

Still I am getting the Gateway Login Screen.

I am in confusion where we can apply this code.

Please help me.

Thanks&Regards

Sridevi