var datePickerDivID = "datepicker";
var iFrameDivID = "datepickeriframe";
    	
	var dayArrayShort = new Array('日', '一', '二', '三', '四', '五', '六');
	var dayArrayMed = new Array('日', '一', '二', '三', '四', '五', '六');
	var dayArrayLong = new Array('星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六');
	var monthArrayShort = new Array('一', '二', '三', '四', '五', '六', '七', '八', '九', '十', '十一', '十二');
	var monthArrayMed = new Array('一月', '二月', '三月', '四月', '五月', '六月', '七月', '八月', '九月', '十月', '十一月', '十二月');
	var monthArrayLong = new Array('一月', '二月', '三月', '四月', '五月', '六月', '七月', '八月', '九月', '十月', '十一月', '十二月'); 

	var defaultDateSeparator = "/";
	var defaultDateFormat = "ymd";
	var dateSeparator = defaultDateSeparator;
	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 = defaultDateSeparator;
      	   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 (!document.getElementById(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 = 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; 
  
      	   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";
  var crlf = ""; 
  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' onMouseOut='this.className=\"dpTD\";' onMouseOver=' this.className=\"dpTDHover\";' "; 
  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' onMouseOut='this.className=\"dpDayHighlightTD\";' onMouseOver='this.className=\"dpTDHover\";' ";
  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 = " 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 + "\");'>本月</button> "; 
   html += "<button class='dpTodayButton' onClick='updateDateField(\"" + dateFieldName + "\");'>關閉</button><br>";
     		 	
  html += xTD + xTR; 

      	   html += xTABLE;

  document.getElementById(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 if (dateString) {                                                                                    
      dateVal = new Date(dateString);
    } else {                                                                                                    
      dateVal = new Date(); 
    }                                                                                                           
  } 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;

  var pickerDiv = document.getElementById(datePickerDivID);
  pickerDiv.style.visibility = "hidden";  
  pickerDiv.style.display = "none";

  adjustiFrame();
  targetDateField.focus();

      	       	       	   if ((dateString) && (typeof(datePickerClosed) == "function"))                                               
    datePickerClosed(targetDateField);
}

function adjustiFrame(pickerDiv, iFrameDiv)                                                                     
{                                                                                                               
      	       	   var is_opera = (navigator.userAgent.toLowerCase().indexOf("opera") != -1);
  if (is_opera)                                                                                                 
    return;

      	   try {                                                                                                         
    if (!document.getElementById(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 = document.getElementById(datePickerDivID);
    if (!iFrameDiv)                                                                                             
      iFrameDiv = document.getElementById(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 ;
      iFrameDiv.style.display = pickerDiv.style.display; 
    } catch(e) {
    }

  } catch (ee) {
  }
}

function checkDatePicker(dateFieldName){                                    
  var dateFieldValue = document.getElementById(dateFieldName).value; 
  var emptyFieldMsg = '日期欄位不得空白!!';
  var errorFormatMsg = '日期欄位格式錯誤!!';
      	                       
  if (/./.test(dateFieldValue)==true){                                                                          
	var isvalidDate=/(19|20)\d\d([- /.])(0[1-9]|1[012])\2(0[1-9]|[12][0-9]|3[01])/.test(dateFieldValue); 
 	  if (isvalidDate == false) alert(errorFormatMsg);
	}
}