php - 通过单个按钮更新MySQL中的行

I have a button, it is inside a while loop that displays all data in the table.
NOTE: All data in the table displays fine.

while($row = mysql_fetch_array($rs_admin))
                {
<form class='form-horizontal' method='post' action='check_managedBorrow.php'>
    <input type='hidden' class='form-control' name=".$row['borrow_id']." id=".$row['borrow_id']." placeholder='Quantity'>
    <td><button type='submit' class='btn btn-primary'>Confirm</button></td>
                }

But in the check_managedBorrow.php it gives me an error that it is not define. How can I put the specific borrow_id for each loop, so that I can UPDATE them?
PS. Any method will do as long as the borrow_id is specified.

Your Input element needs a consistent name in order to read the value again in your check_managedBorrow.php

<input type='hidden' class='form-control' name="BorrowID" value=".$row['borrow_id']." placeholder='Quantity'>

You should be able to access the value as $_POST['BorrowID'] in the receiving file check_managedBorrow.php

There is also the closing </form> tag missing