CGI code snipit needed today!

I need a simple code snipit or modification added to the attached [login to view URL] feedback form script. The code needed is for anti-flood. This is to protect the form from repeated submissions in a short period of time. Ex. user continuously hits refresh and the form submission keeps sending and sending. This can be done with some sort of time limiter based on IP that will not allow another submission for say 3 min or whatever the admin wants. There should be an error message and redirect when this code is triggered. This is a a no-brainer for coders. You must test and make sure it works perfectly before sending it to me. Please review the code attached and only bid if you can produce work within 24 hours. $30 is the max for such a small piece of work. Thanks