Konuyu hortlatmak istemem ama ayni hatayi bende aliyorum. nasil cozebilirim bunu. yazi tipi utf den degil onu biliyorum. buyrun kodlar

<head>
<meta http-equiv="Content-Language" content="tr">
</head>

<body bgcolor="#000080">

<p align="center">&nbsp;</p>
<table border="1" width="100%" id="table1" style="border-width: 0px">
	<tr>
		<td style="border-style: none; border-width: medium" width="361">&nbsp;</td>
		<td style="border-style: none; border-width: medium" width="368">
		<p align="left"><b><font color="#FFFFFF">**ADMİNSTRATOR 
		PANELİ</font></b></p>
		<p>&nbsp;</p>
		<p>&nbsp;</p>
		<div style="position: absolute; width: 325px; height: 100px; z-index: 1; left: 402px; top: 128px" id="katman1">
			<form method="POST" action="index.php?islem=login">
			<table border="1" width="100%" id="table2" height="100">
				<tr>
					<td width="60"><font size="2" color="#FFFFFF">Kullanıcı</font></td>
					<td><input type="text" name="kullanici" size="28"></td>
				</tr>
				<tr>
					<td width="60"><font size="2" color="#FFFFFF">Şifre</font></td>
					<td><input type="password" name="sifre" size="28"></td>
				</tr>
				<tr>
					<td width="60">&nbsp;</td>
					<td><input type="submit" value="Gönder" name="B1"><input type="reset" value="Sıfırla" name="B2"></td>
				</tr>
			</table>
		</div>
		<p>&nbsp;</p>
		<p>&nbsp;</p>
		<p>&nbsp;</p>
		<p align="center"><b><font color="#FFFFFF" size="2">COPYRİGHT **.NET</font></b></p>
		<p>&nbsp;</td>
		<td style="border-style: none; border-width: medium">&nbsp;</td>
	</tr>
</table>


<?php
ob_start();
session_start();
$kullanici 	= $_POST['kullanici'];
$sifre		= $_POST['sifre'];
$islem 	= $_GET['islem'];
switch($islem){
case login:
if($kullanici == admin and $sifre == asdfgh){
echo "Basarili bir sekilde giris yaptiniz";
$_SESSION['admin'] = $kullanici;
$_SESSION['sifre'] = $sifre;
header ("Location: admin.php");

}else{

echo "Kullanici adi veya sifreniz yanlis lutfen kontrol ediniz";
}
break;
}
?>