[Javascript] firing submit event

[Todd Andrew Love]

Hello all,
    I'd like to ask the advice of this wonderful list. I am using a bar code
scanner and would like to automatically fire the form submit event when the
bar code is finished scanning. Anyone know of a way to do this? It can be IE
only.

I've tried firing it on the "onkeyup" event, but it submits the form
multiple times (one for each character in the bar code). It looks like it is
working, but it's actually submitting multiple times. I need 1 submit, this
is a must.

I've tried "onChange", but you have to click outside of the field to fire
it.

Anyone know of an event to fire when the length of a field = a certain # of
characters?

What I'm creating is an employee "timeclock" where they "sign" in and out.
So, it checks against a db to make sure their last access was the opposite
of what they're doing now (in vs. out etc).

Any ideas would be appreciated.

Thanks!
Todd