Works for me. I think you might be running the script each time instead of binding it to a key? It's a macro script so you run it once and then it will show up in: "Main menu > Customize > Customize UI > Keyboard tab > Category: Custom Keys" From there you bind it to a key.
/agreed. I've been writing photoshop scripts for years, and was really afraid of actually coding MaxScripts, basically because you have to know what everything is called internally. Knowing that MaxScript has it's own help file, and then just googling things you don't understand will get you a very, VERY long ways.