การแก้ไขรูปของสินค้าในคลังค่ะ ข้อมูลทุกอย่างแก้ไขให้ยกเว้นรูปค่ะะ

<?php
	include('conn.php');
	
	
	$pro_id = $_GET['pro_id'];
	$pro_name = $_POST['pro_name'];
	$pro_color = $_POST['pro_color'];
	$pro_detail = $_POST['pro_detail'];
	$pro_price = $_POST['pro_price'];
	$pro_cate = $_POST['pro_cate'];
	$pro_amount = $_POST['pro_amount'];
	$pro_img = $_POST["pro_img"];
	
	if (empty($pro_img["size"])){ 
		$filename =  $oldpic; 
	}else 
	{ 
		$filename = $oldpic;        
		@unlink("../img/product/$filename"); 
		$filetemp = $pic["tmp_name"];         
		copy($filetemp, "../img/product".$filename);      
	}   
	
	$sql = "INSERT INTO product ( pro_id, pro_cate, pro_name, pro_color, pro_detail, pro_price, pro_img, pro_amount)
							VALUES ('$pro_id', '$pro_cate', '$pro_name', '$pro_color', '$pro_detail', '$pro_price', '$pro_img', '$pro_amount')";
	
	$sql = "UPDATE product SET  
								pro_cate = '$pro_cate',
								pro_name = '$pro_name',
								pro_color = '$pro_color',
								pro_detail = '$pro_detail',
								pro_price = '$pro_price',
								pro_img = '$pro_img',
								pro_amount = '$pro_amount'
					WHERE pro_id = $pro_id ";
				
	$row = mysql_query($sql);
	if($row)
	{
	echo "<script language='JavaScript'>
			alert('แก้ไขข้อมูลสินค้าสำเร็จแล้ว');
			window.location.href = 'admin_product.php';
	   </script>";
	}
	else
	{
		echo "ไม่สามารถแก้ไขข้อมูลสินค้าได้ [".$sql."]";
	}
	
?>