dynamically reformat input in javascript to add commas to numbers -

i have issue number inputting. user enters large number many zeros, , missing 1 or 2 0 difficult accurately count them.

i think javascript can work out showing user number have inducted, formatted commas.

eg:

input: | 1230000000000 |

result: 1,230,000,000,000

how accomplished?

use following function in javascript

function addcommas(nstr) {     nstr += '';     x = nstr.split('.');     x1 = x[0];     x2 = x.length > 1 ? '.' + x[1] : '';     var rgx = /(\d+)(\d{3})/;     while (rgx.test(x1)) {         x1 = x1.replace(rgx, '$1' + ',' + '$2');     }     return x1 + x2; } 

example

addcommas('9999999.00') // 9,999,999.00