asp.net: RegisterStartupScript from ScriptManagerProxy, possible?

I need to run some javascript after an update panel updates, this update panel is in a Usercontrol located in a page that has a MasterPage. The MasterPage has a ScriptManager and the Usercontrol has a ScriptManagerProxy.

in the UserControl I am calling:

ScriptManagerProxyControl.Page.RegisterStartupScript(Guid.开发者_如何学JAVANewGuid().ToString(), "alert('hello');");

but nothing is happening.

All the exmaples I see use ScriptManager, but this is not available as its on the master page.

Any ideas?

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I found this codeproject article that solves my problem.

http://www.codeproject.com/KB/ajax/hourglassajax.aspx