code delete php

<?php
if(isset($_GET["pro"]) && $_GET["pro"]=="hapus"){
$kode_kategori=$_GET["kode"];
$sql="Delete from `tb_kategori` where `kode_kategori`='$kode_kategori'";
$exe=mysql_query($sql);

if($exe){
    echo"<script>alert('Hapus data  $kode_kategori berhasil');document.location.href='?mnu=kategori'</script>";
    }//exe
else{
    echo"<script>alert('Gagal Hapus data $kode_kategori gagal');document.location.href='?mnu=kategori'</script>";
}

}

?>