Koneksi MYSQL PHP MYSQL CLose Koneksi

<?php
$host="localhost";
$user="root";
$pass="";
$db="db_toko";
$koneksi_db=mysql_connect($host,$user,$pass);
$cari_db=mysql_select_db($db);
if ($cari_db) {
 echo "Database Ada";
  mysql_close($koneksi_db);
 }
else {
  echo "Database Tidak Ada";
  mysql_close($koneksi_db);
 }
?>