php mysql ช่วยดูโค้ดแบ่งหน้าให้ผมหน่อยครับบบบบบบบบบบบ ช่วยหน่อยครับ

<? 
		if(isset($_GET['page'])){
			$page=$_GET['page'];
		}
		
		if(!isset($_GET['start'])){
			$start = 0;
		}else{
			$start=$_GET['start'];
		}	
		$limit = '50';
		
		$sql="select * from menu1 where id1 = '1' ";
		$sql2 ="select * from menu1 where id1 = '1' order by id1 DESC LIMIT $start,$limit  ";
		
		
		$result=mysql_query($sql) or die("Select product error_all!!!");
		$num=mysql_num_rows($result);
		$total=$num;
		
		
		$result2=mysql_query($sql2) or die("Select product error!!!");
		$num2=mysql_num_rows($result2);

		$count_tr=0;
		?>
            <tr>
              <?
		while($data=mysql_fetch_array($result)){
			$product =$data['id1'];						
			
			if($count_tr==4){
				$count_tr=0;
				echo "</tr><tr><tr><td>&nbsp;</td></tr>";
			}
			$count_tr++;
		  ?>
              <td align="center" valign="top"><div align="left"></div> 
                <div align="justify"><?php echo $data['detail'];?></div>
                <div align="center"></div><div align="center"></div><div align="center"></div></td>
              <? }?>
              <? if($num==1){?>
              <? }if($num<=2){?>
              <? }if($num<=3){?>
              <? }?>