Get page data from iframe

[Guest]

I've created a main page that contains a coupe of iframes, i.e. main.aspx
contains 1.aspx and 2.aspx from 2 iframes. How could I use code behind to get
page data from both 1.aspx and 2.aspx? For example, a user enters a text
string into TextBox1 of 1.aspx and types a text string into TextBox2 of
2.aspx, how could I get both of them into the main.aspx by code behind when a
Save button is clicked?

More clear, I used 1.aspx and 2.aspx as the data collection pages, the
main.aspx is to process them. But I'm still in Framework v1.1, I'm not using
the master page feature of Framework v2.0.

bbsbob