I have a user contol hosted in a webform. The user control interfaces with an
http component.
When the user control loads, a request is sent to the http component. It
takes around 10 seconds before a response is returned.
While this is happening the webform cannot do any other processing.

I want to use a client callback to free up the web form while the
usercontrol is busy doing its stuff.
I have got it working fine if I generate the client call back from the
OnClientClick event of a button.
However, my requirement is that the client callback happens from the user
control page load.  The work i am doing HAS to happen when the user control
loads.

- I have been unable access the client side page load of the user control.
(i have tried using Attributes.Add("onload", callbackScript
- I have been unable to use RegisterClientScriptBlock to do the work. ie.
this.Page.ClientScript.RegisterClientScriptBlock(typeof(string), "startup",
callbackScript", true); (The message box shows, but the callback does not
happen)

Has anyone come accross this same scenario?

Many thanks,