Limiting members to one-time options

[Atlanticas]

I would like to do surveys and special contests for my members, but somehow control them from not submiting too many times. I would love to redirect them to a page or message that indicated they've already entered this survey. Is this complex or simple? And what info would you need from my database/php to help me?

[Perad]

You could make people enter a valid e-mail to enter, you can then check the e-mail against your db and see if they have already entered.

EDIT: If they are already members, you could add a new table for each servey. One of your columns could be user_id. When the member clicks the button first time their user_id will be saved. If they click it a second time it will check for the members id and reject the second application.

[Atlanticas]

How can I do this? The web site is closed to only members, so they must login first.

[Perad]

Are you running a forum? How are your members... err members?

[Atlanticas]

Not a forum but some kind of PHP based MySQL database, not good with lingo and terms. You can login, access a Myacct area where you can change your password, email, etc.