<?php
include 'conn.php'; 
$post=$_GET['post'];

$query= mysql_query("SELECT min(cost) as mincost, iqid, warranty FROM cost WHERE postid='$post' GROUP BY iqid, warranty") or die(mysql_error());
while($row = mysql_fetch_array($query)){
$iqid=$row['iqid'];
$mincost=$row['mincost'];

$doup = mysql_query("UPDATE cost SET lowest='yes' WHERE cost=$mincost AND postid=$post") or die(mysql_error());
	if($doup){
	echo $mincost.'&nbsp;&nbsp;'. $iqid.'<br>';
	}
}
?>