How to Add an Aweber Opt-in Form to WordPress?

Comment on WordPress Hacks by Gabor.

Hi Dave

I put Aweber code into a text widget on Talian 05, and it works fine to sign up to mailing list, just when I return to the site it pops up the opt-in box again to sign up. I have to click the X to close it, not a big deal, but might be a little confusing for a visitor and less professional. I was switching settings but it always come back to this. How can I go around it, so when some one signed up, gets returned to the actual page?

Regards, Gabor