var datePickerDivID = "datepicker";
var iFrameDivID = "datepickeriframe";

var dayArrayShort = new Array('ne', 'po', 'ut', 'sr', 'če', 'pe', 'su');
var dayArrayMed = new Array('ne', 'po', 'ut', 'sr', 'če', 'pe', 'su');
var dayArrayLong = new Array('ne', 'po', 'ut', 'sr', 'če', 'pe', 'su');
var monthArrayShort = new Array('Siječanj', 'Veljača', 'Ožujak', 'Travanj', 'Svibanj', 'Lipanj', 'Srpanj', 'Kolovoz', 'Rujan', 'Listopad', 'Studeni', 'Prosinac');
var monthArrayMed = new Array('Siječanj', 'Veljača', 'Ožujak', 'Travanj', 'Svibanj', 'Lipanj', 'Srpanj', 'Kolovoz', 'Rujan', 'Listopad', 'Studeni', 'Prosinac');
var monthArrayLong = new Array('Siječanj', 'Veljača', 'Ožujak', 'Travanj', 'Svibanj', 'Lipanj', 'Srpanj', 'Kolovoz', 'Rujan', 'Listopad', 'Studeni', 'Prosinac');
 
// these variables define the date formatting we're expecting and outputting.   
// If you want to use a different format by default, change the defaultDateSeparator
// and defaultDateFormat variables either here or on your HTML page.
var defaultDateSeparator = "/";        // common values would be "/" or "."
var defaultDateFormat = "dmy"    // valid values are "mdy", "dmy", and "ymd"
var dateSeparator = defaultDateSeparator;
var dateFormat = defaultDateFormat;


function displayDatePicker()
{
	var dateFieldName = "calendar";
	var dtFormat = "dmy";
	var dtSep = ".";
	
  var targetDateField = document.getElementById(dateFieldName);
 
  // if we weren't told what node to display the datepicker beneath, just display it
  // beneath the date field we're updating
    var displayBelowThisObject = targetDateField;
 
  // if a date separator character was given, update the dateSeparator variable
  if (dtSep)
    dateSeparator = dtSep;
  else
    dateSeparator = defaultDateSeparator;
 
  // if a date format was given, update the dateFormat variable
  if (dtFormat)
    dateFormat = dtFormat;
  else
    dateFormat = defaultDateFormat;
 
  var x = displayBelowThisObject.offsetLeft;
  var y = displayBelowThisObject.offsetTop + displayBelowThisObject.offsetHeight ;
 
  // deal with elements inside tables and such
  var parent = displayBelowThisObject;
  while (parent.offsetParent) {
    parent = parent.offsetParent;
    x += parent.offsetLeft;
    y += parent.offsetTop ;
  }
 
  drawDatePicker(targetDateField, x, y);
}


/**
Draw the datepicker object (which is just a table with calendar elements) at the
specified x and y coordinates, using the targetDateField object as the input tag
that will ultimately be populated with a date.

This function will normally be called by the displayDatePicker function.
*/
function drawDatePicker(targetDateField, x, y)
{
  var dt = new Date();
  // the datepicker table will be drawn inside of a <div> with an ID defined by the
  // global datePickerDivID variable. If such a div doesn't yet exist on the HTML
  // document we're working with, add one.
  if (!document.getElementById(datePickerDivID)) {
    // don't use innerHTML to update the body, because it can cause global variables
    // that are currently pointing to objects on the page to have bad references
    //document.body.innerHTML += "<div id='" + datePickerDivID + "' class='dpDiv'></div>";
    var newNode = document.createElement("div");
    newNode.setAttribute("id", datePickerDivID);
    newNode.setAttribute("class", "dpDiv");
    newNode.setAttribute("style", "visibility: hidden;");
    document.body.appendChild(newNode);
  }
 
  // move the datepicker div to the proper x,y coordinate and toggle the visiblity
  var pickerDiv = document.getElementById(datePickerDivID);
  pickerDiv.style.position = "absolute";
  pickerDiv.style.left = x + "px";
  pickerDiv.style.top = y + "px";
  pickerDiv.style.visibility = (pickerDiv.style.visibility == "visible" ? "hidden" : "visible");
  pickerDiv.style.display = (pickerDiv.style.display == "block" ? "none" : "block");
  pickerDiv.style.zIndex = 10000;
 
  // draw the datepicker table
  refreshDatePicker(dt.getFullYear(), dt.getMonth(), dt.getDate());
}


/**
This is the function that actually draws the datepicker calendar.
*/
function refreshDatePicker(year, month, day)
{
  // if no arguments are passed, use today's date; otherwise, month and year
  // are required (if a day is passed, it will be highlighted later)
  var thisDay = new Date();
 
  if ((month >= 0) && (year > 0)) {
    thisDay = new Date(year, month, 1);
  } else {
    day = thisDay.getDate();
    thisDay.setDate(1);
  }
 
  // the calendar will be drawn as a table
  // you can customize the table elements with a global CSS style sheet,
  // or by hardcoding style and formatting elements below
  var crlf = "\r\n";
  var TABLE = "<table class='dpTable' cellspacing=0>" + crlf;
  var xTABLE = "</table>" + crlf;
  var TR = "<tr class='dpTR'>";
  var TR_title = "<tr class='dpTitleTR'>";
  var TR_days = "<tr class='dpDayTR'>";
  var TR_todaybutton = "<tr class='dpTodayButtonTR'>";
  var xTR = "</tr>" + crlf;
  var TD = "<td class='dpTD'>";    // leave this tag open, because we'll be adding an onClick event
  var TD_title = "<td colspan=5 class='dpTitleTD'>";
  var TD_buttons = "<td class='dpButtonTD'>";
  var TD_todaybutton = "<td colspan=7 class='dpTodayButtonTD'>";
  var TD_days = "<td class='dpDayTD'>";
  var TD_selected = "<td class='dpDayHighlightTD'>";    // leave this tag open, because we'll be adding an onClick event
  var xTD = "</td>" + crlf;
  var DIV_title = "<div class='dpTitleText'>";
  var DIV_selected = "<div class='dpDayHighlight'>";
  var xDIV = "</div>";
 
  // start generating the code for the calendar table
  var html = TABLE;
 
  // this is the title bar, which displays the month and the buttons to
  // go back to a previous month or forward to the next month
  html += TR_title;
  html += TD_buttons + "&nbsp;" + xTD;
  html += TD_title + DIV_title + monthArrayLong[ thisDay.getMonth()] + xDIV + xTD;
  html += TD_buttons + "&nbsp;" + xTD;
  html += xTR;
 
  // this is the row that indicates which day of the week we're on
  html += TR_days;
  for(i = 0; i < dayArrayShort.length; i++)
    html += TD_days + dayArrayShort[i] + xTD;
  html += xTR;
 
  // now we'll start populating the table with days of the month
  html += TR;
 
  // first, the leading blanks
  for (i = 0; i < thisDay.getDay(); i++)
    html += TD + "&nbsp;" + xTD;
 
  // now, the days of the month
  do {
    dayNum = thisDay.getDate();
    TD_onclick = "";
    
    if (dayNum == day)
      html += TD_selected + TD_onclick + DIV_selected + dayNum + xDIV + xTD;
    else
      html += TD + TD_onclick + dayNum + xTD;
    
    // if this is a Saturday, start a new row
    if (thisDay.getDay() == 6)
      html += xTR + TR;
    
    // increment the day
    thisDay.setDate(thisDay.getDate() + 1);
  } while (thisDay.getDate() > 1)
 
  // fill in any trailing blanks
  if (thisDay.getDay() > 0) {
    for (i = 6; i > thisDay.getDay(); i--)
      html += TD + "&nbsp;" + xTD;
  }
  html += xTR;
 
  // add a button to allow the user to easily return to today, or close the calendar
  var today = new Date();
  var todayString = "Today is " + dayArrayMed[today.getDay()] + ", " + monthArrayMed[ today.getMonth()] + " " + today.getDate();
  html += TR_todaybutton + TD_todaybutton;
  html += xTD + xTR;
 
  // and finally, close the table
  html += xTABLE;
 
  document.getElementById(datePickerDivID).innerHTML = html;
}