JS(Add comma sepration into the amount)

//A simple javascript function to decoration of numerics specially amount with comma seprated ex: "10,000"

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;

}