urgent help on javascript

Question

I have a web page, say Page1.aspx containing 2 controls - a textbox and a button.
i click the button to open another page say Page2.aspx, using window.showModalDialog containing another textbox and a button.
i type something on this textbox and click the button on Page2.aspx.
what i need is that Page2.aspx should close and whatever was typed on the it's textbox should get copied to the textbox on Page1.aspx