ทำไมเวลา edit มันตรงจำนวนเงินค่ามันเข้าซ้ำกันอะครับรบกวนช่วยดูทีครับ

function findTotal(id){
    
  
    var arr112 = document.getElementsByName('amount');
    var tot = 0;
    


         		 for(var j=0;j<arr112.length;j++){
         		 	
                            if(parseInt(arr112[j].value))
                    tot += parseInt(arr112[j].value);


              			
              			console.log("a="+arr112);
       			}
        console.log("arr112="+arr112);
        console.log("tot="+tot);
    
   
    document.getElementById('total').value = tot;

}

<?php
 echo "เลขใบสั่งซื้อ&nbsp;"  .$fetched_row["page_num"];
$result_set=mysql_query($sql_query);
	if(mysql_num_rows($result_set)>0)
	{

		$i=0;
		while($row = mysql_fetch_row($result_set))
		{

			$i = $i+1;
			
			?>
				<tr>
			    		
			    		<td><div align="center"><?php echo $row[0]; ?></div></td>
			    		
			    		<td><input type="hidden" name="aedit_id<?php echo $i?>" value="<?php echo $row[0]; ?>">

			    			<input type="text" name="item<?php echo $i ?>" placeholder="item" value="<?php echo $row[2]; ?>" required /></td>
			    		<td>
			    		<input type="text" name="desc1<?php echo $i ?>" placeholder="desc1" value="<?php echo $row[5]; ?>" required /></td>
			    		
			    		<td><input type="text" name="q_1<?php echo $i ?>" id="q_1<?php echo $i ?>" placeholder="q_1" value="<?php echo $row[6]; ?>" onkeyup="doMath(<?php echo $i; ?>)" required /></td>
			    		<td><input type="text" name="unti<?php echo $i ?>" placeholder="unit" value="<?php echo $row[7]; ?>" required /></td>
			    		<td><input type="text" name="unit_price<?php echo $i ?>" id="unit_price<?php echo $i ?>" placeholder="unti_price" value="<?php echo $row[8]; ?>" onkeyup="doMath(<?php echo $i; ?>)" required /></td>
			    		<td>
			    			<input type="text" name="amount" id="amount<?php echo $i ?>" onblur="findTotal(<?php echo $i?>)" maxlength="60" value="<?php echo $row[9];?>"> </td>
			    		
			    		
			    		
			    		
			    	</tr>
			    	 
			
			<!--<tr>
				<td><input type="hidden" name="aedit_id<?php echo $i ?>" value="<?php echo $row[0]; ?>">
					<input type="text" name="item<?php echo $i ?>" placeholder="item" value="<?php echo $row[2]; ?>" required /></td>
		<td><input type="text" name="q_1<?php echo $i ?>" id="q_1<?php echo $i ?>" value="<?php echo $row[6]; ?>"  onkeyup="doMath(<?php echo $i; ?>)"maxlength="60"></td>
		<td><input type="text" name="desc1<?php echo $i ?>" placeholder="desc1" value="<?php echo $row[5]; ?>" required /></td>
<td><input type="text" name="unit_price<?php echo $i ?>" id="unit_price<?php echo $i ?>" value="<?php echo $row[7]; ?>"  onkeyup="doMath(<?php echo $i; ?>)"maxlength="60"></td>
			<td><input type="text" name="total<?php echo $i ?>" id="total<?php echo $i ?>" maxlength="60"> </td>

			    		
		</tr>-->
		
			
					
			


	<?php
		}
	}
	else
	{
		?>
		 <tr>
        <th colspan="3">ไม่พบข้อมูล</th>
        </tr>
        <?php
	}
?>

$amount = $_POST['amount'];

if(isset($_POST['btn-update']))
{
	for($i=1;$i<=(int)($_POST["hdnLine"]);$i++)
	{
	
	$item = $_POST['item'.$i];
	$desc1 = $_POST['desc1'.$i];
	$q_1 = $_POST['q_1'.$i];
	$unti = $_POST['unti'.$i];
	$unit_price = $_POST['unit_price'.$i];
	
	
	
	$sql_query = "UPDATE users SET item1='$item',desc1='$desc1',q_1='$q_1',unti='$unti',unti_price='$unit_price',amout1='$_POST['amount']' WHERE user_id=".$_POST["aedit_id$i"];



	var_dump($sql_query);
	if(mysql_query($sql_query))
	{
		?>
		<script type="text/javascript">
		alert('Data Are Updated Successfully');
	//	window.location.href='index.php';
		</script>
		<?php
	}