newbie webmaster

For almost three days i was stuck on how to prevent visitor submiting form more than once. Three thing that I thought:
1. I got script from http://www.portalaska.com/hidden - I tried on my server, it worked, great result .. But when I upload . Nothing happened, the database would not react as I wish.
2. With header(205 :Refresh content) and redirect to a new page. Did not provide result (Or I did not understand how it works?)
Does anybody know?