I am collecting a text area value(number in decimal ) using its id to a javascript variable, adding another variable value (number in decimal), and displaying the result in same html page

text area code:

<div class="input-resp"><span><input  class="textbox" id="num" name="count" type="text" size="5" maxlength="3"  value="" /></span></div>

passing value to var and adding it to another var

var a = document.getElementById('num').value;
var b = 1000;
var c = parseFloat(a) + parseFloat(b); 

passing var c to div id test

document.getElementById("test").innerHTML = c;

html for test id

<div id="test"></div>

But here, whenever I am updating the text area with new number, the final output is not updating instantly.I have refresh the page manually to get new value. Is there anyway I update the value without a page refresh ?

I am collecting a text area value(number in decimal ) using its id to a javascript variable, adding another variable value (number in decimal), and displaying the result in same html page

text area code:

<div class="input-resp"><span><input  class="textbox" id="num" name="count" type="text" size="5" maxlength="3"  value="" /></span></div>

passing value to var and adding it to another var

var a = document.getElementById('num').value;
var b = 1000;
var c = parseFloat(a) + parseFloat(b); 

passing var c to div id test

document.getElementById("test").innerHTML = c;

html for test id

<div id="test"></div>

But here, whenever I am updating the text area with new number, the final output is not updating instantly.I have refresh the page manually to get new value. Is there anyway I update the value without a page refresh ?

• javascript
• html

• Where is your jQuery and where did you define the variable data? And further more.. how are you doing this? With a click event? – putvande Commented Jul 27, 2013 at 17:05
• @putvande : 'data' was a typo.variables are a,b and c.there is no click,iwould like to update the value whenever I type in textarea – acr Commented Jul 27, 2013 at 17:10

1 Answer 1

If it's going to update whenever you type into the input, you need an event handler:

document.getElementById('num').onkeyup = function() {
    var a = 1000 + parseFloat(this.value);
    document.getElementById("test").innerHTML = a || 0;
}

FIDDLE