The "!"

[TheVig]

Ok...so this right here for the ShowDialog:
if(!ShowDialog("Drinks" &Drinks &controls)) ret

This is saying what exactly?

Being that this works to call:
ShowDialog("Drinks" &Drinks &controls)

Why use the "if" and "ret".

When would ShowDialog be Zero?

Sorry to be such a question-bug about this; it seems pretty useful and important, but why or how I haven't got a clue.

I haven't written anything that seems to need this, but it there are a lot of codes I don't really understand that use this and I feel like I am missing out on something.

Thanks Quite a Lot for your help!