prevent from votting more than once

rutin

Hello there,

Pardon my english, is my second !

I am having trouble with my poll, so i would like to ask you very kindly if you could help me. Poll is using mysql.

How can i prevent visitor from votting more than once. I have tried with cookie.
It gives me "Cant modify header...." Is is possible that i could do something with visitors IP address ?

Can you please help me with my CODE, give sample what i need to put.Thank you !!!

I have on beginning of php file this

<? if (!isset ($submit)) { //not press vote or result

Than it starts reads from mysql if there is any polls setup !

<? 

$sel_poll = mysql_query("SELECT * from poll WHERE status='on'");
if (mysql_num_rows($sel_poll)>0){  // if no poll exist
$sel_nr = rand(0, mysql_num_rows($sel_poll)-1);
mysql_data_seek($sel_poll, $sel_nr);
$row_poll = mysql_fetch_array($sel_poll);
?>
                    <?
echo "<strong>$row_poll[1]</strong>";        

?>

Than it starts to read from mysql for any answer !

<? for ($m=2;$m<=11;$m++){
  if ($row_poll[$m] <> ""){ //if I have answer


?>

After all is satisfied pls. setup form for votting, and display !

<td><span class="style7">
              <input name="vote" type="radio" value="<? echo $m;?>">
              <? echo $row_poll[$m];?></span></td>
          </tr>
          <? }} ?>
          <tr>
            <td> <span class="style7">
              <input name="idp" type="hidden" value="<? echo $row_poll[0] ?>">
              <input type="submit" name="submit" value="Vote" class="butoanepoll">
              <input type="submit" name="submit" value="Result" class="butoanepoll">
            </span></td>
          </tr>
              </table>
            </form>
            <span class="style6">

If visitors votes, start writting to mysql table by adding new record.


<? 
   } //if no poll exist
   }
      if ($submit == "Vote") {          

        if ($vote ==2) $updres = mysql_query("UPDATE poll SET result1 = result1+1 WHERE idp = " . $idp);
      if ($vote ==3) $updres = mysql_query("UPDATE poll SET result2 = result2+1 WHERE idp = " . $idp);
      if ($vote ==4) $updres = mysql_query("UPDATE poll SET result3 = result3+1 WHERE idp = " . $idp);
      if ($vote ==5) $updres = mysql_query("UPDATE poll SET result4 = result4+1 WHERE idp = " . $idp);
      if ($vote ==6) $updres = mysql_query("UPDATE poll SET result5 = result5+1 WHERE idp = " . $idp);
      if ($vote ==7) $updres = mysql_query("UPDATE poll SET result6 = result6+1 WHERE idp = " . $idp);
      if ($vote ==8) $updres = mysql_query("UPDATE poll SET result7 = result7+1 WHERE idp = " . $idp);
      if ($vote ==9) $updres = mysql_query("UPDATE poll SET result8 = result8+1 WHERE idp = " . $idp);
      if ($vote ==10) $updres = mysql_query("UPDATE poll SET result9 = result9+1 WHERE idp = " . $idp);
      if ($vote ==11) $updres = mysql_query("UPDATE poll SET result10 = result10+1 WHERE idp = " . $idp);


}//if submit=vote       

   ?>
      </span></TD>
  </TR>
  <TR class="style12">
    <TD>
<?

//Display results from 


$sql="SELECT * FROM poll WHERE idp = '$idp'";
$result = mysql_query($sql);
$row= mysql_fetch_array($result);


$total=$row[result1]+$row[result2]+$row[result3]+$row[result4]+$row[result5]+$row[result6]+$row[result7]+$row[result8]+$row[result9]+$row[result10];



//show ansers

echo "<table class=\"style7\">";
echo "<tr><td class=\"style7\" colspan=\"2\"><b>$row[1]</b></td></tr>";
for ($t=1;$t<=10;$t++){
  $varib="answer".$t;
  $varic="result".$t;
  if ($row[$varic]<>0){
   $proc=$row[$varic]/$total;
   $proc=100*$proc;
   $proc=number_format($proc, 2, '.', '');
   $lung=1*round($proc);
 }else{
  $proc=0;
  $lung=0;
 }

  if ($row[$varib]<>""){
  echo "<tr>
    <td class=\"style12\" width=\"50%\">$row[$varib]</td>
 </tr><tr>
    <td class=\"style12\" >";
 if ($lung > 0){
  echo "<img src=\"slike/leftbar.gif\" width=7><img src=\"slike/mainbar.gif\" width=\"$lung\" height=\"15\"><img src=\"slike/rightbar.gif\" width=7>";
 }
 echo "&nbsp;$proc%&nbsp;($row[$varic])</td>
  </tr>";
  }
  }  

  echo "</table>";
       ?>

I am very sorry for posting so much on this forum.
Thank you all for reading my post.

Kudose

Setting a cookie would be the way to go since some IP addresses are dynamic, although the user could just delete the cookie.

In any case, did you try setting your cookie before any content is being sent to the browser?

You get the "Cannot modify headers..." error when you have already sent info to the browser.

i.e.

Just after you start your "if submitted" portion of your script, before any output, set your cookie.

Hope that helps...

rutin

Thanky you very much for your reply.
How can i hide this form and show results only if user has voted once ? Without header location !

Kudose

<?php
if(isset($_COOKIE['cookie_name'])){
//show results
} else {
//show the form
}
?>

rutin

Thank you once more for very quick reply.
I have placed the cookie on mashine.

it looks like this

voted
1
[url]www.mydomain.net/[/url]
1536
1663155328
29682857
2140638192
29682773
*

Where in my code i should place this : if than else
Where ever i put it, it doesnt seem to work.
The form is still there visible to the visitors.
I dont wanted to be there, i want the form to hide if user has voted.

I think you are suggestion that i divide my php file into function that with this "if than else " i call each function.
Note very good with that. Learnig php.
Please help me.
This is where i have placed cookie

<? 
	  } //if no poll exist
	  }

setcookie("voted", $idp, time()+36000);


	if ($submit == "Vote") { 			   			
if ($vote ==2) $updres = mysql_query("UPDATE poll SET result1 = result1+1 WHERE idp = " . $idp);
if ($vote ==3) $updres = mysql_query("UPDATE poll SET result2 = result2+1 WHERE idp = " . $idp);
if ($vote ==4) $updres = mysql_query("UPDATE poll SET result3 = result3+1 WHERE idp = " . $idp);
if ($vote ==5) $updres = mysql_query("UPDATE poll SET result4 = result4+1 WHERE idp = " . $idp);
if ($vote ==6) $updres = mysql_query("UPDATE poll SET result5 = result5+1 WHERE idp = " . $idp);
if ($vote ==7) $updres = mysql_query("UPDATE poll SET result6 = result6+1 WHERE idp = " . $idp);
if ($vote ==8) $updres = mysql_query("UPDATE poll SET result7 = result7+1 WHERE idp = " . $idp);
if ($vote ==9) $updres = mysql_query("UPDATE poll SET result8 = result8+1 WHERE idp = " . $idp);
if ($vote ==10) $updres = mysql_query("UPDATE poll SET result9 = result9+1 WHERE idp = " . $idp);
if ($vote ==11) $updres = mysql_query("UPDATE poll SET result10 = result10+1 WHERE idp = " . $idp);


}//if submit=vote							

				  ?>

Thank you.

Kudose

I do not know your whole code, but here is a snippet that should get you on your way.

<?php
//if there is no cookie
//and there is no form submit:

if((!$_COOKIE['voted']) && (!_POST['submit'])){
//put all of your code pertaining to
//the poll form BEFORE the submit here
}

//if submit has been clicked:

if ($_POST['submit']) {                           

setcookie("voted", $idp, time()+36000);
$vote = $_POST['vote']; 
if ($vote ==2) $updres = mysql_query("UPDATE poll SET result1 = result1+1 WHERE idp = " . $idp);
if ($vote ==3) $updres = mysql_query("UPDATE poll SET result2 = result2+1 WHERE idp = " . $idp);
if ($vote ==4) $updres = mysql_query("UPDATE poll SET result3 = result3+1 WHERE idp = " . $idp);
if ($vote ==5) $updres = mysql_query("UPDATE poll SET result4 = result4+1 WHERE idp = " . $idp);
if ($vote ==6) $updres = mysql_query("UPDATE poll SET result5 = result5+1 WHERE idp = " . $idp);
if ($vote ==7) $updres = mysql_query("UPDATE poll SET result6 = result6+1 WHERE idp = " . $idp);
if ($vote ==8) $updres = mysql_query("UPDATE poll SET result7 = result7+1 WHERE idp = " . $idp);
if ($vote ==9) $updres = mysql_query("UPDATE poll SET result8 = result8+1 WHERE idp = " . $idp);
if ($vote ==10) $updres = mysql_query("UPDATE poll SET result9 = result9+1 WHERE idp = " . $idp);
if ($vote ==11) $updres = mysql_query("UPDATE poll SET result10 = result10+1 WHERE idp = " . $idp);

//do the rest of your updates to the db
//and show the data from the db here

}//end if vote submitted
?>

rutin

Thank you.... I think i get you. This is much better than my code.
I got error which i cant solve.

Right there where is the line about cookie

if((!$_COOKIE['voted']) && (!_POST['submit'])){

Here is the code


<? 


//if there is no cookie 
//and there is no form submit: 

if((!$_COOKIE['voted']) && (!_POST['submit'])){ 
<?
<td>
              <input name="vote" type="radio" value="<? echo $m;?>">
              <? echo $row_poll[$m];?></td>
          </tr>
          <? }} ?>
          <tr>
            <td> 
              <input name="idp" type="hidden" value="<? echo $row_poll[0] ?>">
              <input type="submit" name="submit" value="Vote" class="butoanepoll">
              <input type="submit" name="submit" value="Result" class="butoanepoll">
            </span></td>
          </tr>
              </table>
            </form>
            <span class="style6">    

			<?


//put all of your code pertaining to 
//the poll form BEFORE the submit here 
} 
<?
<?
//if submit has been clicked: 

if ($_POST['submit']) {                            

setcookie("voted", $idp, time()+36000); 
$vote = $_POST['vote'];  

if ($vote ==2) $updres = mysql_query("UPDATE poll SET result1 = result1+1 WHERE idp = " . $idp); 
if ($vote ==3) $updres = mysql_query("UPDATE poll SET result2 = result2+1 WHERE idp = " . $idp); 
if ($vote ==4) $updres = mysql_query("UPDATE poll SET result3 = result3+1 WHERE idp = " . $idp); 
if ($vote ==5) $updres = mysql_query("UPDATE poll SET result4 = result4+1 WHERE idp = " . $idp); 
if ($vote ==6) $updres = mysql_query("UPDATE poll SET result5 = result5+1 WHERE idp = " . $idp); 
if ($vote ==7) $updres = mysql_query("UPDATE poll SET result6 = result6+1 WHERE idp = " . $idp); 
if ($vote ==8) $updres = mysql_query("UPDATE poll SET result7 = result7+1 WHERE idp = " . $idp); 
if ($vote ==9) $updres = mysql_query("UPDATE poll SET result8 = result8+1 WHERE idp = " . $idp); 
if ($vote ==10) $updres = mysql_query("UPDATE poll SET result9 = result9+1 WHERE idp = " . $idp); 
if ($vote ==11) $updres = mysql_query("UPDATE poll SET result10 = result10+1 WHERE idp = " . $idp); 

//do the rest of your updates to the db 
//and show the data from the db here 


$sql="SELECT * FROM poll WHERE idp = '$idp'";
$result = mysql_query($sql);
$row= mysql_fetch_array($result);

$total=$row[result1]+$row[result2]+$row[result3]+$row[result4]+$row[result5]+$row[result6]+$row[result7]+$row[result8]+$row[result9]+$row[result10];

echo "<table class=\"style7\">";
echo "<tr><td class=\"style7\" colspan=\"2\"><b>$row[1]</b></td></tr>";
for ($t=1;$t<=10;$t++){
  $varib="answer".$t;
  $varic="result".$t;
  if ($row[$varic]<>0){
	  $proc=$row[$varic]/$total;
	  $proc=100*$proc;
	  $proc=number_format($proc, 2, '.', '');
	  $lung=1*round($proc);
	}else{
		$proc=0;
		$lung=0;
	}

  if ($row[$varib]<>""){
  echo "<tr>
    <td class=\"style12\" width=\"50%\">$row[$varib]</td>
	</tr><tr>
    <td class=\"style12\" >";
	if ($lung > 0){
		echo "<img src=\"slike/leftbar.gif\" width=7><img src=\"slike/mainbar.gif\" width=\"$lung\" height=\"15\"><img src=\"slike/rightbar.gif\" width=7>";
	}
	echo "&nbsp;$proc%&nbsp;($row[$varic])</td>
  </tr>";
  }
  }  

  echo "</table>";



}//end if vote submitted


				  ?>

Kudose

Should be:

if((!$_COOKIE['voted']) && (!$_POST['submit'])){

Sorry about that.

Also, about mid-way through your script, you have two <?'s in there. You'll need to remove one of the <? tags.

rutin

my dear friend, thank you for helping me all the time.
its very kind of you. i wasnot able to fix it. I am very sad.
i am attachind the entire file. can you please show once for all.

teach me a lesson please.

what i am doing wrong ?

Thanks for previous tip.

This file i am attaching contains HTML code, it might have strange look if you view it directly via browser. I am afraid you will need to go via view source code.