// This function gets called when the end-user clicks on some date.
function selected(cal, date) {
    cal.sel.value = date; // just update the date in the input field.
    if (cal.dateClicked && (cal.sel.id == "sel1" || cal.sel.id == "sel2"))
        // if we add this call we close the calendar on single-click.
        // just to exemplify both cases, we are using this only for the 1st
        // and the 3rd field, while 2nd and 4th will still require double-click.
        cal.callCloseHandler();
}

// And this gets called when the end-user clicks on the _selected_ date,
// or clicks on the "Close" button.  It just hides the calendar without
// destroying it.
function closeHandler(cal) {
    cal.hide();                        // hide the calendar
    // cal.destroy();
    _dynarch_popupCalendar = null;
}

// This function shows the calendar under the element having the given id.
// It takes care of catching "mousedown" signals on document and hiding the
// calendar if the click was outside.
function showCalendar(id, format, showsTime, showsOtherMonths) {
    var el = document.getElementById(id);
    if (_dynarch_popupCalendar != null) {
        // we already have some calendar created
        _dynarch_popupCalendar.hide();                 // so we hide it first.
    } else {
        // first-time call, create the calendar.
        var cal = new Calendar(1, null, selected, closeHandler);
        // uncomment the following line to hide the week numbers
        // cal.weekNumbers = false;
        if (typeof showsTime == "string") {
            cal.showsTime = true;
            cal.time24 = (showsTime == "24");
        }
        if (showsOtherMonths) {
            cal.showsOtherMonths = true;
        }
        _dynarch_popupCalendar = cal;                  // remember it in the global var
        cal.setRange(1900, 2070);        // min/max year allowed.
        cal.create();
    }
    _dynarch_popupCalendar.setDateFormat(format);    // set the specified date format
    _dynarch_popupCalendar.parseDate(el.value);      // try to parse the text in field
    _dynarch_popupCalendar.sel = el;                 // inform it what input field we use
    
    // Muestro el calendario debajo del textbox.
    _dynarch_popupCalendar.showAtElement(el, "Br");
    return false;
}