// 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, bindname, format, dateattr)
{
  var el = document.getElementById(bindname);
  if (calendar != null)
  {
    // we already have some calendar created
    calendar.hide();                 // so we hide it first.
    calendar = null;
  }

  // first-time call, create the calendar.
  var cal;
  if (dateattr)
  {
    // Bind calendar to dateattribute widgets
    cal = new Calendar(false, null, changeWidget, closeHandler);
  }
  else
  {
    // Bind calendar to textfield.
    cal = new Calendar(false, null, changeTextField, closeHandler);
  }
  // uncomment the following line to hide the week numbers
  // cal.weekNumbers = false;
  cal.dateattrId = id;
  cal.setDisabledHandler(ATK.DateAttribute.checkDisabled);
  calendar = cal;                  // remember it in the global var
  cal.setRange(1900, 2070);        // min/max year allowed.
  cal.create();

  calendar.setDateFormat(format);    // set the specified date format
  if (dateattr)
  {
    // get current value from dateattribute widgets
    var val = ATK.DateAttribute.getValue(id);
	var year = val.year;
	if(year=='') year = new Date().getFullYear();
    calendar.parseDate(year + '-' + val.month + '-' + val.day);
  }
  else
  {
    // get current value from textfield
    calendar.parseDate(el.value);      // try to parse the text in field
  }
  calendar.sel = el;                 // inform it what input field we use
  calendar.dateattrId = id;
  calendar.showAtElement(el);        // show the calendar below it

  return false;
}

// This function gets called when the end-user clicks on some date.
function changeWidget(cal, date)
{
  ATK.DateAttribute.setValue(cal.dateattrId, { year: date.substr(0,4), month: parseInt(date.substr(5,2), 10), day: parseInt(date.substr(8,2), 10) });
}

function changeTextField(cal, date)
{
  cal.sel.value = date; // just update the date in the input field.

  // trigger on change event  
  if (document.createEventObject){
    // dispatch for IE
    var evt = document.createEventObject();
    cal.sel.fireEvent('onchange',evt)
  }
  else{
    // dispatch for firefox + others
    var evt = document.createEvent("HTMLEvents");
    evt.initEvent('change', true, true ); // event type,bubbling,cancelable
    cal.sel.dispatchEvent(evt);
  }  
}

// 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
}