theForm is undefined

See more:

ASP.NET

Javascript

I create a website and implement ICallbackEventHandler in default.aspx page when I call

WebForm_DoCallback(args1, arg2, callback, 'comment', null, false);

Then I am getting theForm is undefined error in following line. Can anybody solve this error why it is occurring?

function WebForm_InitCallback() {
    var count = theForm.elements.length;
    var element;

Thanks in advance
Imrankhan