// Popup a window to show the currency converter
function popupCurrency() {
    var newwin;

    var posX = (screen.width - 405) / 2;
    var posY = 40;  // static value

    newwin = window.open('/currency_converter.html', 'currency_converter', 'top=' + posY + ',left=' + posX + ',status=no,toolbar=no,location=no,menubar=no,resizable=yes,scrollbars=no,height=305,width=405', false);
    if (newwin) {
        newwin.focus();
    }
}