I would go further:
var %text = $editbox($active)
if ($len(%text) >= 1) && ($left(%text,1) != $chr(47)) {
Note that I reversed the conditions, too.
Also looked like there was a space missing between one of the ) { pairs.
Yeah, I just posted the code to replace what he said without redoing (or looking at) what I had originally posted.

I didn't notice a missing space, but maybe I'm blind.
