[SELF RESOLVED] Script Timing out

[modpluz]

why does this code keep timing out?

function getStep($u){
    $sql1 = "SELECT Step FROM tblUsers WHERE User_ID=$u";
    $res1 = mysql_query($sql1) or die("An error has occured<br>".mysql_error());
        if(mysql_num_rows($res1) > 0){
         while($ro_w = mysql_num_rows($res1)){
         $ms = kill_null($ro_w['Step'], 0);
         }
        } else {
         $ms = "-1";
        }
         return $ms;
}