Help with navigation

I need to do something whereby when you click on a button in the menu its related window opens up. Then, when you click on a different button in the menu, the current window closes before the new window appears.

Here is the FLV file of my work in progress
http://www.megaupload.com/?d=P7URMJV0

When you click on CV (button) i want the Porfolio (window) to animate/close, for example fade out, BEFORE the CV window opens.

The same goes for when you have the CV button selected and go to click the portfolio, i want the CV window to close before the portfolio window opens.

I hope I have explained this okay.

If anybody knows of any good tutorials for navigation (ie. the window side of things) please link them )

Thanks in advance,
James.