This could probably be it - I tried this with v8.1 and 8.2 of splitter (the official release in the Infragistics.Web assembly) and even with just a splitter on the page and nothing else except ScriptManager, it was working fine. The Preview Assembly is I guess an earlier CTP that had this problem (probably missing Page.RegisterRequiresPostBack call) and had been addressed in the official version.

Thanks again for reporting that. 

I am using preview version so i suspect thats the problem

 Nah i didnt see any hot fix available, so the hidden linkbutton on the page works, not ideal but it works.

Hey robifw6

Can you pls tell me exactly which version of NA you are using ? Did you install any hotfix ?

Thanks.

Ok i am going to tell you this one last time because you dont understand..

 I am aware that the code is auto generated, what i am SAYING is that if you dont have a linkbutton on a page(which when you place on teh page it generates the var theforms... __dopostback), the web splitter doesnt work. To do a test, put a websplitter on a page, with no other controls that implement ipostbackeventhandler and see the websplitter do nothing, draw a js error saying theform is undefined, and see the web splitter arrow right up the top.

 I dont need to attach a page as an example as i have told you this 3 times now.

This is a bug full stop, i now have to put a linkbutton which is hidden just to get this web splitter to work, very poor design, relying on auto generated code from the .net framework to be there, thats not a good assumption to be made..