Question

Presented alongside a polling facility on a webpage is the following input fields that enables the visitor (voter) to enter their details in a raffle for a hamper as a reward for their effort in taking part in the poll.

The raffle entry form script is not attached to the poll script. All inputs in the raffle entry form script are validated and the info is sent to a flatfile. It is a short poll lasting only 7 days on different topics that might arise from time to time for a small town forum. (ip is also collected)

Name  :<input type="text" name="visitor" /><br /><br />
Email :<input type="text" name="visitormail" /><br /><br />
Phone :<input type="text" name="visitorphone"/><br /><br />

On submission the ‘Thank You’ page advises the visitor that their details will be used once in the raffle for the hamper. In other words the visitor could go back and fill in the form again and submit, requiring that I check for and weed out multiple entries from the flatfile before completing the Random Number draw for the hamper!

The Question Is there a simple way to install something that prevents the visitor from attempting multiple entries into the draw?

Answer 1

I would log the IP as well (see $_SERVER variable). Then you can narrow down duplicates by IP. Not always the most fool proof method.

Another approach could be a cookie.