Get value from calculate it by using textbox? Javascript

Question

Good day,

I want to calculate values from Textbox1 and Textbox2 and the answer in Textbox3. So first I gave the three text boxes Id and Name. Textbox1 is called number1, Textbox2 is called number2 and Textbox3 is called uitkomst.
Then, I used a button and said onclick activate,this function is in Javascript and in Javascript I said getValue() from Textbox1 and Textbox2 by using getElementID() and named these variables num1 and num2 respectively,and because I only want to multiply. I just said var answer = num1 * num2;. Then I used getElement() to print it in Textbox3. But still it doesn`t work.

<script type="text/javascript" language="javascript">
function meten(){
   var num1 = document.getElementById("number1").value;
   var num2 = document.getElementById("number2").value;    
   var answer  = num1 * num2;
   document.getElementById("uitkomst").value = answer;
}    
</script>


L:<input name="number1" id="number1" pattern="[0-9.]+" type="number"  onkeypress='return event.charCode >= 48 && event.charCode <= 57' required /> *

 B:<input name="number2" name="number2" pattern="[0-9.]+" type="number"  onkeypress='return event.charCode >= 48 && event.charCode <= 57' required /> 
<br>
<input type="button"  value="bereken" onclick="meten()"/> 
<br>
Total: <input  name="uitkomst" id="uitkomst" value="" onFocus="blur()" />

Do you get any error or isn't there any event triggered? try putting alerts in javascript to check if its being called and executed properly. — Ymartin

Amit Joki Amit Joki · Accepted Answer · 2014-11-29T11:46:28

The problem is that you've not set id attribute for number2 but instead you've set two name attributes, so the document.getElementById('number2') fails. Change one of them to id

B:<input id="number2" name="number2" pattern="[0-9.]+" type="number"  onkeypress='return event.charCode >= 48 && event.charCode <= 57' required />

DEMO

Get value from calculate it by using textbox? Javascript

1 Answers