Scripts Combining in controls Toolkit Control AJAX of time load up Speed
In using the ToolkitScriptManager you get optimized script sources.
But there exists still one Issue. Every Script takes its own request.
To Boost and to reduce the number of requests your page needs to make for all of the individual scripts.
just add this Handler to your web site "CombineScriptHandler.ashx"
Then use the ToolkitScriptManager instead of the straight ScriptManager in your pages, specifying the CombineScriptsHandlerUrl to point to the handler you just added, similar to this (note: the ScriptMode="Release" trick works here too).