Problem using Master pages

Question

Hi all i have done this code as per my requirement in my website for selecting all check boxes which works fine with normal web page. But if use this along with master page i am unable to get the desired output i required can any one help me...

The reference site is as follows

http://dotnetspeaks.net/post/Checking-all-CheckBoxes-in-a-GridView-using-JQuery.aspx