$q = mysql_query("SELECT ID FROM UserDetails ORDER BY power DESC");
 $x=1;
 while($row=mysql_fetch_array($q)){
 $id=$row['ID'];
 $r = mysql_query("update UserDetails set powerrank=".$x." where ID='$id'");
 $x = $x + 1;
 }
 $q = mysql_query("SELECT ID FROM UserDetails ORDER BY covert DESC");
 $x=1;
 while($row=mysql_fetch_array($q)){
 $id=$row['ID'];
 $r = mysql_query("update UserDetails set covertrank=".$x." where ID='$id'");
 $x = $x + 1;
 }

 $q = mysql_query("UPDATE UserDetails SET Rank = (powerrank + covertrank)/2");

$q = mysql_query("SELECT ID FROM UserDetails ORDER BY rank ASC");
 $x=1;
 while($row=mysql_fetch_array($q)){
 $id=$row['ID'];
 $r = mysql_query("update UserDetails set rank=".$x." where ID='$id'");
 $x = $x + 1;
 }

}