I got the solution for the issue and it is working fine properly.
Well I am using Visual Studio 2010 Project for my web application.
So when I create any new page it contains 3 files Default.aspx, Default.aspx.cs,
Default.aspx.designer.cs
But when I choose New Website then I get only Default.aspx and Default.aspx.cs.
The same Cron code(javascript) mentioned above working fine for one of my colleague's and he is using Visual Studio 2010 Website.
I copied the same file(without the designer.cs file) with the same code in-fact same letter,
and add in my project and it worked.
Well my Cron motive has been accomplished but I am still confused why it didn't work for me in Project as it is working in Website template. Then I scheduled the cscript.exe to run this .js file in Windows Task Scheduler.
Please comment and guide us why it was not working and it worked in the same project but with a different.