How 2 prevent rePosting vars when browser refreshes

[badboy]

How can I prevent my script from reprocessing the posted vars when users hit reload/refresh from their browser ?

<FORM ACTION="MyForm.php" METHOD="POST">

Thanks

[djcomplex]

on myform.php before you assign your post variables check if they exist

<?php

if ($field1 || $field2)
{
echo 'data submitted';
}

$field1 = $_POST['field1'];
$field2........

get it?

[bubblenut]

Won't work I'm afraid, when a page is refreshed the entire http reqest is resent and reprocessed. You send along a unique key with each request and then check if that key has been processed in the last few hours or something.
eg. (assumes a mysql db)

<?php
//page1.php
//create a key
$key=md5(microtime().'A Unique Key');
?>
<form name="form" method="POST" action="page2.php">
<input type="hidden" name="key" value="<?php echo($key);?>" />
<input type="text" name="var1" />
<input type="submit" name="submit" value="Submit" />
</form>

and then for the page which processes the form

<?php
//page2.php
//db connection stuff
//check the form has been submitted
if(!empty($_POST['submit']) && !empty($_POST['var1']) && !empty($_POST['key'])) {
  $sql="SELECT COUNT(*) FROM formcheck WHERE key='$_POST[key]' && time>".(now()-86400)."'";
  $res=mysql_query($sql) or die(mysql_error());
  $row=mysql_fetch_array($res,MYSQL_NUM);
  if($row[0]!=0) {
    echo('This is a repost ... fail');
    exit();
  } else {
    //process the form
  }
}

Prehapse not very tidily done
:rolleyes: but you get the idea.

HTH
Bubble

[onion2k]

session_start();
if(++$_SESSION['intUserVisits'] == 1) {
  //Do this the first time the page loads.
} else {
  //Otherwise do this.
}

Relies on sessions of course, but it'd be simple enough to rewrite using a $GET or $POST variable instead. (Which is what the code in the post above does)