I have a working solution that implements the MultiHandleSliderExtender control in a test suite and I am trying to get it to work in my ASP.NET 4.0 web page with VS2010. I want it to run inside an accordion control, and I would like to use the default master page that comes with the ASP.NET web site solution. When I copy and paste the MultiHandleSliderExtender control in its final place on my page, and run the solution, I get a jscript runtime error: Microsoft JScript runtime error: 'null' is null or not an object. When I peek with Visual Studio, I see that $get(multiHandleSliderTargetID) returns null, even though multiHandleSliderTargetID has value "TextBox1" as it should be when I hover over this with my mouse.
I had to remove the ToolkitScriptManager as it complained about already having one.
I tried moving it out of the accordion control, but it is still broken. Here is the definition of the control that I am trying to get working. It bahaves as if it does not see the ControlID. Is there some scoping that I am not aware of, or better yet, how can I tag TextBox1 so that it gets exposed with the $get() method?
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