how to in set javascript id in input value

Question

i want to inset my javascript id in to the place of input value .

if i give Interest name input value="100"

how can i get tc named table input value="75"

my input form

    <tr>
                            <th>Loan Amount</th>
                            <th>INTEREST RATE %</th>
    <tr>              
            <tbody>
<td><input disabled type="" name="tc" id="int_amount" class="formcontrol"value=""/></td>
<td><input  type="number" name="Interest" id="input2" onkeyup="calculate();"/ class="form-control" value=""/></td>

            </tr>
            </tbody>

javascript

var vatti = document.pricecal.Interest.value;
var Total = vatti -25;

    if(vatti = null)
    {

        document.getElementById("int_amount").innerHTML  = "Rs:"+" "+Total;

    }
[want out put like this][1]

Answer 1

Hope this helps you.

 function calculate(interest){ var vatti = interest.value; if (vatti != '') { var Total = vatti - 25; document.getElementById("int_amount").value = Total; }else{ document.getElementById("int_amount").value = ''; } } 

 <table> <tbody> <tr> <td><input type="number" name="Interest" id="input2" onkeyup="calculate(this)" onchange="calculate(this)" class="form-control" value=""/></td> <td><input type="" name="tc" id="int_amount" class="formcontrol" value=""/></td> </tr> </tbody> </table> 

Answer 2

设置<input>元素的.value而不是.innerHTML

document.getElementById("int_amount").value  = "Rs:"+" "+Total;

Answer 3

HTML:

<tbody>
  <tr>
    <td><input type="number" name="Interest" id="input2" class="form-control" value=""/></td>
    <td><input type="" name="tc" id="int_amount" class="formcontrol" value=""/></td>
  </tr>
</tbody>

Javascript:

document.getElementById('input2').onkeyup = function() {
    document.getElementById('int_amount').value = (this.value != '') ? 'Rs: ' + (parseInt(this.value)-25) : '';
}