function numbersonly(e, decimal) {
    var key;
    var keychar;

    if (window.event) {
        key = window.event.keyCode;
    }
    else if (e) {
        key = e.which;
    }
    else {
        return true;
    }
    keychar = String.fromCharCode(key);

    if ((key == null) || (key == 0) || (key == 8) || (key == 9) || (key == 13) || (key == 27)) {
        return true;
    }
    else if ((("0123456789").indexOf(keychar) > -1)) {
        return true;
    }
    else if (decimal && (keychar == ".")) {
        return true;
    }
    else
        return false;
}