Function for creating unique md5 keys in a database. If there are duplets, then a new md5-key will be generated. For your use:
function users_md5create($id){
global $mysql_link;
while ($done==0) {
$md5key = md5(time().($id/2).$loop).md5(time().$id.$loop);
$query = "INSERT INTO users_md5create SET md5key='$md5key', fkey='$id', created=UNIX_TIMESTAMP() ";
$mysql_result = mysql_query($query, $mysql_link);
if(mysql_errno($mysql_link)!=1062) $done=1;
$loop++;
}
return($md5key);
}