PHP สร้าง XML error เพราะอะไร - The page contains the following error :

<?php
header("Content-type:text/xml; charset=UTF-8");              
header("Cache-Control: no-store, no-cache, must-revalidate");             
header("Cache-Control: post-check=0, pre-check=0", false);   
echo '<?xml version="1.0" encoding="utf-8"?>';

$objConnect = mysql_connect("localhost","root","root");
$objDB = mysql_select_db("mydatabase");
$strSQL = "SELECT * FROM gallery WHERE 1  ";
$objQuery = mysql_query($strSQL);
?>
<gallery>
	<?
	while($obResult = mysql_fetch_array($objQuery))
	{
	?>
		<image>
			<GalleryID><?=$obResult["GalleryID"];?></GalleryID>
			<Name><?=$obResult["Name"];?></Name>
			<TitleName><?=$obResult["TitleName"];?></TitleName>
			<Thumbnail><?=$obResult["Thumbnail"];?></Thumbnail>
		</image>
	<?
	}
	?>
</gallery>
<?
	mysql_close($objConnect);
?>