A Visual C++ 6.0 IDE question.

A lot of time I like to activate the memory space, work area, debug
windows etc using the keyboard instead of mouse. eg. Alt-3, Alt-4

Not sure why, I guess I find it faster than lifting my fingers off the
keyboard, looking for the mouse, hold the mouse, click on the right
place etc.

So I am wondering once you have open screens on the VC++ IDE using
Alt-3, Alt-4 etc, what is the reverse keystroke to de-activate them.
I find I always have to grab the mouse to click on the little 'x' in
the top right/left corner to get rid of these toolbars.