Sending postback to ajax loaded user controls

I have a set of tabs开发者_JS百科, which all of them together contain alot of data. I am making the tabs load async. I have one button above the tabs used to save changes. I need this button to send a postback to all the loaded user controls (using this). I need the user control to handle this postback so it can save changes.

What do you think? Any suggestions?

Tried doing it, doesn't work. I am going to have to do some magic with updatepanels and a custom postback.