Issue
When ASP.NET controls are rendered their ids sometimes change, like if they are in a naming container. Button1 may actually have an id of ctl00_ContentMain_Button1 when it is rendered, for example.
I know that you can write your JavaScript as strings in your .cs file, get the control’s clientID and inject the script into your page using clientscript, but is there a way that you can reference a control directly from JavaScript using ASP.NET Ajax?
I have found that writing a function to parse the dom recursively and find a control that CONTAINS the id that I want is unreliable, so I was looking for a best practice rather than a work-around.
Solution
Oh, and I also found this, in case anyone else is having this problem.
Use a custom jQuery selector for asp.net controls:
http://john-sheehan.com/blog/custom-jquery-selector-for-aspnet-webforms/
Answered By – NetHawk
Answer Checked By – Dawn Plyler (BugsFixing Volunteer)