Switching between windows

Hi all
Not sure if this is the correct forum for my questions, so apologies in advance

I am dual boxing D3
When i want to swap to the other window of the game i have to use the mouse pointer.
I am trying to work out how to set "x" as the key i can press to swap between the 2 games for looting
I just cant seem to get my old brain to sort it out, everything else works perfectly for me...
Sorry if its a noobish question, i did have a look around but didnt notice anything that made sense to me...
Its bound to be an easy thing to do and i appreciate any help you can give....

[lax]

Happily, when ISBoxer 41 is released, the Quick Setup Wizard includes an obvious way to configure this Hotkey.

Otherwise, in 4 easy steps: Common modifications: Rotate windows

Thank you