got a weird question

abda53

ok.. dont think this is a php issue, but is there a way that i can make a page refresh or do something when someone tries to go back a page?

im running a image voting page (http://www.abda53.com/vote) and im trying to get it so that people cant vote and keep hitting back to give someone like 200 #10 votes..

is there anything i can do about that?

raymie

Unless you make users log in first there is no way to stop duplicate voting, you can just make it harder.

Some sites will stop the same IP address from making a vote twice, this however is fraught with problems.

I would suggest for simplicity that you make the voting page a php script (and hence dealing with the refresh issue) and record the ip or some other fairly unique server variable of the voter and not let them vote again within a specific period.

This is not foolproof but will make it more of a pain for anyone duplicating votes.

You could also try setting a cookie on the users machine, but this would be easy to bypass if they wanted to.

abda53

ok.. the site is written in php with mysql..

lets see... im thinking.. is there a way to record the time the user makes a vote on a specific image, and it will record the time, say for like the last 5 or 10 or so votes including ip address and times.. and then cross reference it that way?

raymie

something like that....

I would possibly have a table with the vote-id assuming that you have several votes on the go at one time, the users info and a timestamp and simply not allow another vote for the same users data, before checking that however I would drop from the table all entries which are before a certain time (ie current timestamp - 300 perhaps (300 = 5 mins)).

abda53

ok sweet. thats a good idea i never thought of that.. im still learning php and mysql so ill see what i can come up with. hope you dont mind the dumb questions

raymie

If you ask a dumb question I will let you know but this subject would not fit into that category - it's just rather sad that there is no foolproof way to achieve what you want.

abda53

ok so im going to try to do this.. when a user votes, it will also update/add the date and time.. like you suggested.. but im not quite sure how to insert that.. here is my form..

<td align=center><table cellspacing=0 cellpadding=2 border=1 bordercolor=#000000 bgcolor=<? print $tablebg ?>><tr valign=middle><td align=center><table border=0 width=460><form action=./ name=_rateForm method=post><input type=hidden name=op value=rate><input type=hidden name=id value="<? print($id); ?>"><tr><td colspan=3 align=center><b><font size=2>Please select a rating to see the next picture.</font></b></td></tr><tr><td></td><td align=center>

raymie

Adding the date/time is actually nothing to with the form.

What you want to do is create a field for it on your table.

You need to decide how you want to store it, I would suggest in your case a mysql timestamp (but you could also use a unix timestamp format).

if using a mysql timestamp simple update it by inserting the record giving it a value of NOW().

abda53

yup thats what i meant.. sorry i didnt mean to actually add it into the form.. im not sure, like on the timestamp part, ive read about it, but i couldnt find anything really the describes how to put it in there.. thanks for such a quick reply too!