[Resolved] problems with variables catching on refresh

[meowmix]

I dont know how to describe this problem, so check this out

http://meowmix.servebeer.com/public/ue/shout.php

Fill it out, hit submit, then hit refresh. It'll post another entry.

Here's the code for the page

          <?
          if (isset($_POST['shoutSubmit'])) {

        require ('variables.php');
        $link = mysql_connect("$mysql_host", "$mysql_login", "$mysql_password") or die("Could not connect");
        mysql_select_db("$mysql_database") or die("Could not select database");
     $name    = $_POST['name'];
     $url     = $_POST['url'];
	     $comment = $_POST['comment'];
        $query = "INSERT INTO $var_table (name, url, comment) VALUES ('$name', '$url', '$comment')";
        $result = mysql_query($query) or die("Database Error: Error #0001");
        unset($_POST['shoutSubmit']);
        mysql_close($link);

      }
      ?>
      <iframe src="read.php" width="300" height="350" frameborder="0" scrolling="yes"></iframe>
      <form enctype="multipart/form-data" method="post" action="<? echo $HTTP_SERVER_VARS['PHP_SELF']; ?>">	     
      <table width="300" border="0" cellspacing="0" cellpadding="2">
          <tr> 
            <td align="right" width="35%">name : </td>
            <td width="65%"> 
              <input type="text" name="name">
            </td>
          </tr>
          <tr> 
            <td align="right" width="35%">website : </td>
            <td width="65%"> 
              <input type="text" name="url">
            </td>
          </tr>
          <tr> 
            <td align="right" width="35%">comments : </td>
            <td width="65%"> 
              <input type="text" name="comment">
            </td>
          </tr>
          <tr align="center"> 
            <td colspan="2">
              <input type="submit" name="shoutSubmit" value="shout!">
            </td>
          </tr>
      </table>
      </form>

read.php is simply a SELECT query. As you can see, I tried to unset the submit button, but that didnt work. It still sends the INSERT query again on refresh.

Any help would be appreciated.

[DeltaRho2K]

You need to do some verification to see if the entry exists, and if so, then don't do the insert... This is pretty basic, and you will no doubtedly need to make some changes to better fit your needs and script, but I think you get the idea... This code will prevent people from posting the same exact message, but only relies on the name, URL and comment.

$verify = mysql_query("SELECT FROM $var_table WHERE name = '$name' AND url = '$url' AND comment = '$comment'"); 
$countverify = mysql_num_rows($verify);

If ($countverify == '0'):
   // put your INSERT code here.

Else:
   // Echo some kind of message to indicate the post is already there.

Endif;

[meowmix]

I was thinking of doing a verification myself, but I was hoping there might have been another way.

Thanks, I'll use that until I can devise some other evil scheme to pull it off.

[edit]

for the record, it's

$verify = "SELECT * FROM $var_table WHERE name='$name' AND url='$url' AND comment='$comment'";
$verifyresult = mysql_query($verify) or die("random error message here!");
$countverify = mysql_num_rows($verifyresult);

[/edit]

[DeltaRho2K]

It's about the only way... The problem is that the variables exist from the POST, and won't go away until you close the browser... Even if you navigate away from the page, you could press the back button to get back to the page, and voila... Refresh, and it does it again...

I think I have seen people use something like the following, which verifies the submit button was pressed, and if not, then won't do the INSERT:

If($submit):
// Then do the post

Else:
// Don't do the post

Endif;

I am not too sure of the exact syntax for this, but I am sure someone like cgraz, stolzyboy, or laserlight probably know what I am talking about, and can help out here...