กดปุ่มที่ทำไว้เพื่อส่งค่าให้เปลี่ยนหน้าเพจ แต่ค้างหน้าเดิมตลอดเลยครับ

  switch (isset($_GET["page"])) {
									case 'media':
										include('/admin/media.php');
										break;
									case 'playlist':
										include('/admin/playlist.php');
										break;
									case 'text':
									  include('/admin/text.php');
										break;
								  case 'layer':
									  include('admin/layer.php');
										break;
									case 'schedule':
									  include('admin/schedule.php');
										break;
									case 'upload':
									  include('admin/upload.php');
										break;
									case 'setting':
									  include('admin/setting.php');
										break;
									default:
										include('admin/main.php');
										break;
								}

	<a href=""><img src="image/top.png"/></a>
	<a href=index.php?page=media><img src="image/media.png"/></a>
	<a href=index.php?page=playlist><img src="image/playlist.png"/></a>
	<a href=index.php?page=text><img src="image/text.png"/></a>
	<a href=index.php?page=layer><img src="image/layer.png"/></a>
	<a href=index.php?page=schedule><img src="image/schedule.png"/></a>
	<a href=index.php?page=upload><img src="image/upload.png"/></a>
	<a href=index.php?page=setting><img src="image/setting.png"/></a>
	<a href=admin/logout.php><img src="image/logout.png"/></a>