Add new or change green button?

[LukeScott]

Hello,

Does anyone know if there is a way to add a fourth color button to every window on Mac OS X (red=close,yellow=minimize,green=zoom).

I wrote an AppleScript to Maximize the current window and tied it to a hot key with FastScript Lite:

tell application "System Events"
	set app_name to name of the first process whose frontmost is true
end tell

tell application "System Events" to tell process app_name
	tell front window
		set position to {0, 0}
		set size to {1280, 1024}
	end tell
	
	try
		click menu item "Zoom To Fit" of menu 1 of menu bar item "View" of menu bar 1
	end try
end tell

I have it tied to a hot key, but it would be better if it were a button... I'd like to either override the zoom button with my AppleScript (which I'd add to), or simply add a new button with a different color to the current AppleScript and use the Zoom button to un-maximize a window (which it does well).

I understand that if it is possible, it's probably not something very easy to do... But I'm wondering if it even is possible.

I'm currently using Leopard.