I'm just trying to figure out how to make the usr's skin go from mainWindow to window1 (they are both in the same interface file.) I tried the variable usr.window but that didn't work, any ideas?

This is ment to allow for right-handed and left-handed gameplay.
Check/Uncheck the Default option in the Edit dialogue box of the windows.
In response to Spunky_Girl
That doesn't help, I'm trying to make a verb that the usr can click to toggle their window.

I tried something similar to this:

if(usr.windowright == 1)
usr.windowright = 0
usr.window = "window1"
usr.windowright = 1
usr.window = "mainWindow"

However it says that usr.window is undefined thus not allowing me to change windows.

Edit: I really just need to know if there is a variable that determines the usr's window and if there is what is it called and do I call it under usr or client.
In response to SadoSoldier
Ok I just tried this:

set category = "Interface"
if(usr.skinright == 1)
usr.skinright = 0
usr.Interface = 'skin.dmf'
usr.skinright = 1
usr.Interface = 'default.dmf'

However it says Interface is an undefined variable. What is the variable name is what I need to know.

Note: I'm basing this on the way icons are used.
In response to SadoSoldier
Okay I just skimmed over the whole DM Guide and I saw nothing that is in any way related to this. Any other resources I should read over that might help?
In response to SadoSoldier
I would not be surprised, as the DM guide was made around version 2 and the skin was brought around 4.0

Did you tried checking out skin tutorials like the one by Lummox JR in Dream Makers guild? Or did you tried checking the skin reference page (Help > Skin)? Did you know about winset()?
Dude, what the heck? Guessing random var names for the win, huh...
There's the DM Reference so you don't really need to do that, but interface stuff is really handled more by the winget() and winset() interface procs rather than by vars (which in the first place naturally wouldn't be on mobs anyway but on clients). Then you'd read the Skin Reference for info about controls, their parameters, and how to operate on them.
In response to GhostAnime
I re-read the the tutorial, I read the skin section involving winset and winget(might be a typo) but I didn't find it, I saw how to return the windows so I tried using that to call the correct window in the verb however all I successfully managed to do was create two windows on login and only your original window worked. So I'm just going to have to scrap this idea but thanks for your help anyway.(Cant afford to spend too much time on one little thing)