If I understand your problem, this might help:
PHP Code:
// check to see if any post data was submitted
if (count($_POST) > 0 )
{
// see if the post is the same as the one we just received
if ($_SESSION['post_hash'] == md5(serialize($_POST)))
{
// if it is kill it by reseting the $_POST array
$_POST = array();
}
else
{
// if not, set 'post_hash' to a string that represents the posted data
$_SESSION['post_hash'] = md5(serialize($_POST));
// add your normal validation and insert code here
//
//
}
}