javascript - Automatic percentage calculator -

i working on code calculate percentage need calculate percentage automatically without submit button, want output calculated percentage without need of user hitting submit button.

here code

input: <input type="text" id="input"/><br /> percent: <input type="text" id="percent" value="50"/>%<br /> output: <input type="text" id="output"/>   function calc() {   var = document.getelementbyid("input").value;   var p = document.getelementbyid("percent").value;   var o = (i/100) * p;   document.getelementbyid("output").value = o; } 

on each of 2 inputs, add onchange="calc();" (updates when user tabs next field) or onkeyup="calc();" (updates whenever user types something).