Modal Popup Extender - how to set values on main page

Hi

I've got a Modal Popup Extender that shows a Pane and greys out the main page in the background. The main page has a Label (Label1) on it and the Pane (Pane1) that is being popped up has a Text Box (Text1) on it.

I want the user to fill in some text in the Text Box on the popped up Pane, and when the user clicks Button1 (the OK button on the Pane), it should take TextBox1.Text and place it in Label1.Text.

How do I do this? I'm using C#. Sorry, I know this is a basic questions for all you AJAX guru's out there. :)

Thanks in advance!

Regards
Edward

try javascript,

label1.value = textbox1.value;