ทำยังไงให้เรียงจากวันที่ล่าสุด ไว้ให้อยู่ข้างบนอันแรกค่ะ

<?php
	function DateThai($strDate)
	{
		$strYear = date("Y",strtotime($strDate))+543;
		$strMonth= date("n",strtotime($strDate));
		$strDay= date("j",strtotime($strDate));
		
		$strMonthCut = Array("","ม.ค.","ก.พ.","มี.ค.","เม.ย.","พ.ค.","มิ.ย.","ก.ค.","ส.ค.","ก.ย.","ต.ค.","พ.ย.","ธ.ค.");
		$strMonthThai=$strMonthCut[$strMonth];
		return "$strDay $strMonthThai $strYear";
	}

	$strDate = "2008-08-14 ";
	
?>

<? 
		include ("ConnectGeneral.php");
		mysql_query ("SET NAMES utf8") or die (mysql_errno());
		$id_knowledge=$_GET['id_knowledge'];
		
		$sql = "SELECT * FROM `knowledge`";
		$result = mysql_query($sql);
		

while($row=mysql_fetch_array($result)){
			$id_knowledge= $row["id_knowledge"];
			$date_knowledge = DateThai($row["date_knowledge"]);
			$head_knowledge= $row["head_knowledge"];
		
			$pic_knowledge= $row["pic_knowledge"];
			
 echo "<tr align='left'>";
echo "<td><img width=70 height=56 src='$pic_knowledge'></td>";
 
 echo "<td class='hactivity'><a href=\"ShowKnowledge1.php?id_knowledge=$id_knowledge\"<base target=_blank ' />$head_knowledge</td>";

echo "<td>$date_knowledge</td>";
}
?>