Hi Senthil,
After looking your code, I can suggest one thing please update getParam script in your java script
alert(document.webserviceCall.getQueryObject().getParam(1,"Site"));
alert(document.webserviceCall.getQueryObject().getParam(1));
alert(document.webserviceCall.getQueryObject().getParam(2,"SFC"));
alert(document.webserviceCall.getQueryObject().getParam(2));
getParam(int ParamNumber): in getParam method you have to pass only Param Number
sometimes if you call wrong method than complete java script wont work that could be the reason for your alert issue you can check for errors in ie ooter left corner.
Below is the URL for basic query template pameter reference.
http://help.sap.com/saphelp_xmii115/helpdata/en/applet_reference_details/ParameterReference.htm
Hope it helps!!
Regards,
Manoj Bilthare