<?php
$dbhost='localhost';
$dbusername='root';
$dbname = 'test';
mysql_connect ($dbhost, $dbusername);
mysql_select_db($dbname) or die('Cannot select database');
$query  = "SELECT * FROM test4"; 
$result = mysql_query($query) or die('Error, query failed'); 
if(!isset($cmd)){
 
while($row = mysql_fetch_array($result)) {
 
$id = $row["id"];
echo "<strong> tom</strong>:  {$row['Tom']}</p>";
echo "<strong> id</strong>:  {$row['id']}</p>";
echo "<p><a href='?cmd=delete&id=$id'>delete</a></p>" ;
   }
}
if($_GET["cmd"]=="delete")
{
$sql = "DELETE FROM test4 WHERE id=$id";
$result = mysql_query($sql);
}
 
?>

$sql = "DELETE FROM test4 WHERE id={$_GET['id']}";