I am creating a new window with specific size settings that closes when the user is done editing info. For some reason, it changes the size of the original window if it was maximized when the button to run this script is pressed. Any ideas?

This is normal Windows behavior, I guess. Yet there may be a remedy. I haven't tested it personally, just saw in a mailing list:

http://www.medeyedbs.com/WindowUtility20.htm

Original author (Kevin Frank) wrote: "...to the best of my knowledge, this plug-in is the only way on the Windows platform to generate a pseudo-dialog (a FileMaker window imitating a modal dialog) while keeping the background window maximized."

In Windows, if one window is maximized, they all are. Since you're using a script, you could use an Adjust Window[Restore] step to ensure that the maximization is undone. I don't know what the effect is if the window *hasn't* been maximized.