// Calendar Support by Julian Robichaux -- http://www.nsftools.com
var datePickerDivID = "datepicker";
var iFrameDivID = "datepickeriframe";

var dayArrayShort = new Array('Z', 'M', 'D', 'W', 'D', 'V', 'Z');
var dayArrayMed = new Array('Zo', 'Ma', 'Di', 'Wo', 'Do', 'Vr', 'Zat');
var dayArrayLong = new Array('Zondag', 'Maandag', 'Dinsdag', 'Woensdag', 'Donderdag', 'Vrijdag', 'Zaterdag');
var monthArrayShort = new Array('J', 'F', 'M', 'A', 'M', 'J', 'J', 'A', 'S', 'O', 'N', 'D');
var monthArrayMed = new Array('Jan', 'Feb', 'Maa', 'Apr', 'Mei', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec');
var monthArrayLong = new Array('Januari', 'Februari', 'Maart', 'April', 'Mei', 'Juni', 'Juli', 'Augustus', 'September', 'Oktober', 'November', 'December');
  
var defaultDateFormat = "dmy"
var dateSeparator = ddS;
var dateFormat = defaultDateFormat;

function displayDatePicker(dateFieldName, displayBelowThisObject, dtFormat, dtSep){
  var targetDateField = document.getElementsByName(dateFieldName).item(0);
  
  if (!displayBelowThisObject)
    displayBelowThisObject = targetDateField;
  
  if (dtSep)
    dateSeparator = dtSep;
  else
    dateSeparator = ddS;
  
  if (dtFormat)
    dateFormat = dtFormat;
  else
    dateFormat = defaultDateFormat;
  
  var x = displayBelowThisObject.offsetLeft;
  var y = displayBelowThisObject.offsetTop + displayBelowThisObject.offsetHeight;
  
  var parent = displayBelowThisObject;
  while (parent.offsetParent) {
    parent = parent.offsetParent;
    x += parent.offsetLeft;
    y += parent.offsetTop;
  }
  
  drawDatePicker(targetDateField, x, y);
}

function drawDatePicker(targetDateField, x, y){
  var dt = getFieldDate(targetDateField.value);
  if (!$(datePickerDivID)) {
    var newNode = document.createElement("div");
    newNode.setAttribute("id", datePickerDivID);
    newNode.setAttribute("class", "dpDiv");
    newNode.setAttribute("style", "visibility: hidden;");
    document.body.appendChild(newNode);
  }
  
  var pickerDiv = $(datePickerDivID);
  pickerDiv.style.position = "absolute";
  pickerDiv.style.left = x + "px";
  pickerDiv.style.top = y + "px";
  pickerDiv.style.width = "150px";
  pickerDiv.style.visibility = (pickerDiv.style.visibility == "visible" ? "hidden" : "visible");
  pickerDiv.style.zIndex = 10000;
  
  refreshDatePicker(targetDateField.name, dt.getFullYear(), dt.getMonth(), dt.getDate());
}

function refreshDatePicker(dateFieldName, year, month, day){
  var thisDay = new Date();
  
  if ((month >= 0) && (year > 0)) {
    thisDay = new Date(year, month, 1);
  } else {
    day = thisDay.getDate();
    thisDay.setDate(1);
  }
  
  var crlf = "\r\n";
  var TABLE = "<table cols=7 class='dpTable'>" + 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>";
  
  var html = TABLE;
  
  html += TR_title;
  html += TD_buttons + getButtonCode(dateFieldName, thisDay, -1, "&lt;") + xTD;
  html += TD_title + DIV_title + monthArrayLong[thisDay.getMonth()] + " " + thisDay.getFullYear() + xDIV + xTD;
  html += TD_buttons + getButtonCode(dateFieldName, thisDay, 1, "&gt;") + xTD;
  html += xTR;
  
  html += TR_days;
  for(i = 0; i < dayArrayShort.length; i++)
    html += TD_days + dayArrayShort[i] + xTD;
  html += xTR;
  
  html += TR;
  
  for (i = 0; i < thisDay.getDay(); i++)
    html += TD + "&nbsp;" + xTD;
  
  do {
    dayNum = thisDay.getDate();
    TD_onclick = " onmouseover=\"this.style.backgroundColor='#E8E8E8';\" onmouseout=\"this.style.backgroundColor='';\" onclick=\"updateDateField('" + dateFieldName + "', '" + getDateString(thisDay) + "');\">";
    
    if (dayNum == day)
      html += TD_selected + TD_onclick + DIV_selected + dayNum + xDIV + xTD;
    else
      html += TD + TD_onclick + dayNum + xTD;
    
    if (thisDay.getDay() == 6)
      html += xTR + TR;
    
    thisDay.setDate(thisDay.getDate() + 1);
  } while (thisDay.getDate() > 1)
  
  if (thisDay.getDay() > 0) {
    for (i = 6; i > thisDay.getDay(); i--)
      html += TD + "&nbsp;" + xTD;
  }
  html += xTR;
  
  var today = new Date();
  var todayString = "Today is " + dayArrayMed[today.getDay()] + ", " + monthArrayMed[today.getMonth()] + " " + today.getDate();
  html += TR_todaybutton + TD_todaybutton;
  html += "<button class='dpTodayButton' onClick='refreshDatePicker(\"" + dateFieldName + "\");'>huidige maand</button> ";
  html += "<button class='dpTodayButton' onClick='updateDateField(\"" + dateFieldName + "\");'>sluit</button>";
  html += xTD + xTR;
  
  html += xTABLE;
  
  $(datePickerDivID).innerHTML = html;
  adjustiFrame();
}

function getButtonCode(dateFieldName, dateVal, adjust, label){
  var newMonth = (dateVal.getMonth() + adjust) % 12;
  var newYear = dateVal.getFullYear() + parseInt((dateVal.getMonth() + adjust) / 12);
  if (newMonth < 0) {
    newMonth += 12;
    newYear += -1;
  }
  
  return "<button class='dpButton' onClick='refreshDatePicker(\"" + dateFieldName + "\", " + newYear + ", " + newMonth + ");'>" + label + "</button>";
}

function getDateString(dateVal){
  var dayString = "00" + dateVal.getDate();
  var monthString = "00" + (dateVal.getMonth()+1);
  dayString = dayString.substring(dayString.length - 2);
  monthString = monthString.substring(monthString.length - 2);
  
  switch (dateFormat) {
    case "dmy" :
      return dayString + dateSeparator + monthString + dateSeparator + dateVal.getFullYear();
    case "ymd" :
      return dateVal.getFullYear() + dateSeparator + monthString + dateSeparator + dayString;
    case "mdy" :
    default :
      return monthString + dateSeparator + dayString + dateSeparator + dateVal.getFullYear();
  }
}

function getFieldDate(dateString){
  var dateVal;
  var dArray;
  var d, m, y;
  
  try {
    dArray = splitDateString(dateString);
    if (dArray) {
      switch (dateFormat) {
        case "dmy" :
          d = parseInt(dArray[0], 10);
          m = parseInt(dArray[1], 10) - 1;
          y = parseInt(dArray[2], 10);
          break;
        case "ymd" :
          d = parseInt(dArray[2], 10);
          m = parseInt(dArray[1], 10) - 1;
          y = parseInt(dArray[0], 10);
          break;
        case "mdy" :
        default :
          d = parseInt(dArray[1], 10);
          m = parseInt(dArray[0], 10) - 1;
          y = parseInt(dArray[2], 10);
          break;
      }
      dateVal = new Date(y, m, d);
    } else {
      dateVal = new Date(dateString);
    }
  } catch(e) {
    dateVal = new Date();
  }
  
  return dateVal;
}

function splitDateString(dateString){
  var dArray;
  if (dateString.indexOf("/") >= 0)
    dArray = dateString.split("/");
  else if (dateString.indexOf(".") >= 0)
    dArray = dateString.split(".");
  else if (dateString.indexOf("-") >= 0)
    dArray = dateString.split("-");
  else if (dateString.indexOf("\\") >= 0)
    dArray = dateString.split("\\");
  else
    dArray = false;
  
  return dArray;
}

function updateDateField(dateFieldName, dateString){
  var targetDateField = document.getElementsByName(dateFieldName).item(0);
  if (dateString)
    targetDateField.value = dateString;
  $(datePickerDivID).style.visibility = "hidden";
  adjustiFrame();
  targetDateField.focus();
  if ((dateString) && (typeof(datePickerClosed) == "function"))
    datePickerClosed(targetDateField);

}


function adjustiFrame(pickerDiv, iFrameDiv){
  if (!$(iFrameDivID)) {
    var newNode = document.createElement("iFrame");
    newNode.setAttribute("id", iFrameDivID);
    newNode.setAttribute("src", "javascript:false;");
    newNode.setAttribute("scrolling", "no");
    newNode.setAttribute("frameborder", "0");
    document.body.appendChild(newNode);
  }
  
  if (!pickerDiv)
    pickerDiv = $(datePickerDivID);
  if (!iFrameDiv)
    iFrameDiv = $(iFrameDivID);
  
  try {
    iFrameDiv.style.position = "absolute";
    iFrameDiv.style.width = pickerDiv.offsetWidth;
    iFrameDiv.style.height = pickerDiv.offsetHeight;
    iFrameDiv.style.top = pickerDiv.style.top;
    iFrameDiv.style.left = pickerDiv.style.left;
    iFrameDiv.style.zIndex = pickerDiv.style.zIndex - 1;
    iFrameDiv.style.visibility = pickerDiv.style.visibility;
  } catch(e) {
  }
}

var minYear=2000;
var maxYear=2100;

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year){
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   } 
   return this
}

function isDate(dtStr){
	var daysInMonth = DaysArray(12)
	var pos1=dtStr.indexOf(ddS)
	var pos2=dtStr.indexOf(ddS,pos1+1)
	var strDay=dtStr.substring(0,pos1)
	var strMonth=dtStr.substring(pos1+1,pos2)
	var strYear=dtStr.substring(pos2+1)
	strYr=strYear
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
	}
	month=parseInt(strMonth)
	day=parseInt(strDay)
	year=parseInt(strYr)
	if (pos1==-1 || pos2==-1){
		alert("Voer de datum in volgens dit formaat: dd-mm-yyyy")
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		alert("Er is geen geldige maand ingevoerd: " + month)
		return false
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert("Er is geen geldige dag ingevoerd")
		return false
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		alert("Er is geen geldig jaar ingevoerd. Geef een jaar op tussen "+minYear+" en "+maxYear)
		return false
	}
	if (dtStr.indexOf(ddS,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, ddS))==false){
		alert("Er is geen geldige datum ingevoerd")
		return false
	}
return true
}