mysql tablodan satır silmede sorun

$baglan=mysql_connect("localhost", "altantaban", "123123")or die ("Database ile baglanti kurulamadi!!");
@mysql_select_db("altan") or die ("veritabani ile baglanti kurulamadi!!");
$islem= mysql_query("select * from liste ; ", $baglan);
echo "<b>Bulunan Kayıt Sayısı:</b>".mysql_num_rows($islem)."<br><br>";
			$degisken=<<<EOF
<form action="randevu_sil.php" method="post" />			
<input type ="submit" value="sil" name="sil" />
EOF;
while ($dizi=mysql_fetch_row($islem)) 
		{
					echo "<b>Adı:</b>".$dizi[0]."<br>"; 
					echo "<b>Tel:</b>".$dizi[1]."<br>";
					echo "<b>Konu:</b>".$dizi[2]."<br>";
					echo "<b>Saat:</b>".$dizi[3]."<br>";
					echo "<b>Mesaj:</b>".$dizi[4]."<br>";
					echo "$degisken"."<br>";
					echo "----------------<br>";
		}
mysql_close($baglan);					
?>

<?php
$baglan=mysql_connect("localhost", "altantaban", "123123")or die ("Database ile baglanti kurulamadi!!");
@mysql_select_db("altan") or die ("veritabani ile baglanti kurulamadi!!");
$islem= mysql_query("select * from liste ; ", $baglan);
     $sil = mysql_query ("
      DELETE FROM liste WHERE Ad = '$ad'
	 ");
	 if ($sil) { 
	 echo "silindi" ;
	 }else{
	 echo "silinmedi".mysql_error();
	 }
$a=<<<EOF
<br>
<a href=http://ilanyerim.com/randevu3.php>Geri Dön</a>
EOF;
echo $a;
?>

echo "<input type ="hidden" value=".$dizi[0]." name="ad" />

echo "<input type ="hidden" value=".$dizi[0]." name="ad" />

echo "<b>Adı:</b>".$dizi[0]."<br>";

echo "<input type =\"hidden\" value=\".$dizi[0].\" name=\"ad\" />";

$ad = $_POST["ad"]

while ($dizi=mysql_fetch_row($islem)) 
{

echo "<input type =\"hidden\" value=\".$dizi[0].\" name=\"ad\" />";
echo "<input type =\"hidden\" value=\".$dizi[1].\" name=\"tel\" />";
echo "<input type =\"hidden\" value=\".$dizi[2].\" name=\"konu\" />";
// diye devam eder.

}