I know that in the next version of ASP.NET we\'ll finally be able to set the clientids on System.Web controls without the framework doing it for us in a quasi-intelligent wa
I have often run in to this "problem" while developing in asp.net webforms. In most cases I tend to use the css class of the element.
jQuery(".My .Container12")
Before starting to manipulate the id:s, perhaps that is a way you can handle it aswell? It's a simple solution.