function onlyAmountChars(e) {
    var keynum;
    var keychar;
    var numcheck;

    if (window.event) // IE
    {
        keynum = e.keyCode;
    }
    else if (e.which) // Netscape/Firefox/Opera
    {
        keynum = e.which;
    }

    //Only allow numbers, comma and nonchars (backspace, delete etc.)
    if ((keynum >= 58 && keynum <= 126) || (keynum >= 32 && keynum <= 43) || (keynum >= 45 && keynum <= 47) || (keynum >= 128 && keynum <= 255)) {
        return false;
    }
    else {
        return true;
    }
}