Auto update text box depending on an input box

javascript, jquery

Solution

Quick solution:

html code:

<input type="text" name="ltc" id="input-ltc">
<input type="text" name="btc" readonly id="input-btc">

javascript:

var inputLtc = document.getElementById('input-ltc'),
inputBtc = document.getElementById('input-btc');

var constantNumber = 2;

inputLtc.onchange = function() {
   var result = parseFloat(inputLtc.value) * constantNumber;
   inputBtc.value = !isNaN(result) ? result : '';
};

jsfiddle: http://jsfiddle.net/6KT4R/

edit:

You may use onkeydown to get result when typing.

Problem

I have these two input boxes here. ``` <input type="text" name="ltc"> <input type="text" name="btc" readonly> ``` Ok, now what I want is..that when I enter some value in the first textbox, then that value would be multiplied by a constant number and the result would be displayed in the btc textbox. I guess this can be done via jQuery, but I have no idea as to how I can do it(because of my limited/no knowledge in jQuery). Can somebody guide me? Thanks.

Original source