我在Codeigniter做发票。我想计算金额，我可以做第一行（动态创建）。但第二行，它不工作。有人能帮我吗？我希望我的问题是直截了当的...
动态插入行的代码

function addRow(tableID) { 
  var table = document.getElementById(tableID);
  var rowCount = table.rows.length-1;
  var row = table.insertRow(rowCount); 
        //Column 1  
        var cell1 = row.insertCell(0);
        cell1.innerHTML = '<input type="text" name="item[]" id="item">'
        //Column 2  
        var cell2 = row.insertCell(1);
        cell2.innerHTML = '<input type="number" name="qty[]" id="qty" onkeyup="calc()">'; 
        //Column 3  
        var cell3 = row.insertCell(2);
        cell3.innerHTML = '<input type="number" name="rate[]" id="rate">'; 
        //Column 4  
        var cell4 = row.insertCell(3);
        cell4.innerHTML = '<input type="number" name="tax[]" id="tax">'; 
        //Column 5  
        var cell5 = row.insertCell(4);
        cell5.innerHTML = '<input type="number" name="amound[]" id="amound" readonly>'; 
        //Column 6 
        var cell6 = row.insertCell(5);  
        cell6.innerHTML = '<input id="Button" type="button" value="Delete" class="delete-row btn btn-danger"/>';
      } 

      $(document).on('click', '.delete-row', function() {
        $(this).parents('tr').remove();
      });

这是我的js计算代码

function calc(){
   var textValue1 = document.getElementById('qty').value; 
   var textValue2 = document.getElementById('rate').value;
   var textValue3 = document.getElementById('tax').value;
   var mul = textValue1 * textValue2;
   var tax = mul*(textValue3/100);
   var result = +textValue2 + +tax;

   document.getElementById('amound').value = result; 
 
 }