ASP.NET AJAX and Javascript

[Simic]

I have page on which I am using CollapsiblePanelExtender and JavaScripts.
When Javascripot is directly on the page everything is working good. I am
trying to put those scripts in to the file and to include it with
RegisterStartupScript using either ScriptManager.RegisterStartupScript or
ClientScript.RegisterStartupScript in Page_Load or OnPreRender event.
The Javascript in those cases is not seen objects which are on UpdatePanel
which is showing trough CollapsiblePanelExtender .

Does anybody have some idea?
Thanks.

 

[Simic]

One more thing. On other page where I am using also
CollapsiblePanelExtender when I open page source view I regularly see
objects(grid) html tags. With the first problematic page I don't see
objects. Probably they are saved in view state or similar and that is the
problem.

 

[Simic]

The solution was that I use created name
document.getElementById("ctl00_ContentPlaceHolder1_grdDetails");