php mysql เมื่อนำขึ้น server จริงพบปัญหา javascript ไม่ทำงาน

<?
	session_start();
	include('in_config.php');
	$sql = "SELECT * FROM user WHERE(username='$txtusername' and password='$txtpassword')";
	$dbquery = mysql_query($sql);
	$result = mysql_fetch_array($dbquery);
	if(!$result)
	{
		?>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
		<script language="javascript">
			alert('ขออภัย  คุณระบุข้อมูลผิด');
			window.location.href = "in_left.php";
		</script>
        <?
	}
	else
	{
		if($result["t_id"] == '01')
		{
			?>
			<script language="javascript">
                window.location.href = "a_main.php";
            </script>
            <?
		}
		elseif($result["t_id"] == '02')
		{
			?>
			<script language="javascript">
                window.location.href = "d_main.php";
            </script>
            <?
		}
		elseif($result["t_id"] == '03')
		{
        	?>
			<script language="javascript">
                window.location.href = "m_main.php";
            </script>
            <?
		}
		$_SESSION['username'] = $result["username"];
		$_SESSION['t_id'] = $result["t_id"];
		session_write_close();
	}
?>