autoresponder

I have a website that I am driving traffic to. I want one of those really annoying popups to appear when someone tries to leave the site without signing up for more information. I have existing aweber account for the autoresponder. I can create content for emails but that is it. You will have to create form for info to include: name email phone (if they want a call) best time to call the form will be staic in the website at the bottom and a popup? that appears when they try and leave. I hope that is clear.