// overly simplistic test for IE
isIE = (document.all ? true : false);
// both IE5 and NS6 are DOM-compliant
isDOM = (document.getElementById ? true : false);

// get the true offset of anything on NS4, IE4/5 & NS6, even if it's in a table!
function getAbsX(elt) { return (elt.x) ? elt.x : getAbsPos(elt,"Left"); }
function getAbsY(elt) { return (elt.y) ? elt.y : getAbsPos(elt,"Top"); }
function getAbsPos(elt,which) {
 iPos = 0;
 while (elt != null) {
  iPos += elt["offset" + which];
  elt = elt.offsetParent;
 }
 return iPos;
}

function getDivStyle(divname) {
 var style;
 if (isDOM) { style = document.getElementById(divname).style; }
 else { style = isIE ? document.all[divname].style
                     : document.layers[divname]; } // NS4
 return style;
}

function hideElement(divname) {
 getDivStyle(divname).visibility = 'hidden';
}

// annoying detail: IE and NS6 store elt.top and elt.left as strings.
function moveBy(elt,deltaX,deltaY) {
 elt.left = parseInt(elt.left) + deltaX;
 elt.top = parseInt(elt.top) + deltaY;
}

function toggleVisible(divname) {
 divstyle = getDivStyle(divname);
 if (divstyle.visibility == 'visible' || divstyle.visibility == 'show') {
   divstyle.visibility = 'hidden';
 } else {
   fixPosition(divname);
   divstyle.visibility = 'visible';
 }
}

function setPosition(elt,positionername,isPlacedUnder) {
 var positioner;
 if (isIE) {
  positioner = document.all[positionername];
 } else {
  if (isDOM) {
    positioner = document.getElementById(positionername);
  } else {
    // not IE, not DOM (probably NS4)
    // if the positioner is inside a netscape4 layer this will *not* find it.
    // I should write a finder function which will recurse through all layers
    // until it finds the named image...
    positioner = document.images[positionername];
  }
 }
 elt.left = getAbsX(positioner);
 elt.top = getAbsY(positioner) + (isPlacedUnder ? positioner.height : 0);
}

// how reliable is this test?
isIE = (document.all ? true : false);
isDOM = (document.getElementById ? true : false);

// Initialize arrays.
var months = new Array("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");
var daysInMonth = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
var displayMonth = new Date().getMonth();
var displayYear = new Date().getFullYear();
var displayDivName;
var displayElement;

function getDays(month, year) {
// Test for leap year when February is selected.
if (1 == month)
   return ((0 == year % 4) && (0 != (year % 100))) ||
      (0 == year % 400) ? 29 : 28;
else
   return daysInMonth[month];
}

function getToday() {
// Generate today's date.
this.now = new Date();
this.year = this.now.getFullYear();
this.month = this.now.getMonth();
this.day = this.now.getDate();
}

// Start with a calendar for today.
today = new getToday();

function newCalendar(eltName,attachedElement) {
if (attachedElement) {
   if (displayDivName && displayDivName != eltName) hideElement(displayDivName);
   displayElement = attachedElement;
   }
   displayDivName = eltName;
          today = new getToday();
          var parseYear = parseInt(displayYear + '');
          var newCal = new Date(parseYear,displayMonth,1);
          var day = -1;
          var startDayOfWeek = newCal.getDay();
          if ((today.year == newCal.getFullYear()) &&
                (today.month == newCal.getMonth()))
   {
             day = today.day;
          }
          var intDaysInMonth =
             getDays(newCal.getMonth(), newCal.getFullYear());
          var daysGrid = makeDaysGrid(startDayOfWeek,day,intDaysInMonth,newCal,eltName)
   if (isIE) {
      var elt = document.all[eltName];
      elt.innerHTML = daysGrid;
          } else if (isDOM) {
      var elt = document.getElementById(eltName);
      elt.innerHTML = daysGrid;
   } else {
      var elt = document.layers[eltName].document;
      elt.open();
      elt.write(daysGrid);
      elt.close();
   }
}

function incMonth(delta,eltName) {
  displayMonth += delta;
  if (displayMonth >= 12) {
    displayMonth = 0;
    incYear(1,eltName);
  } else if (displayMonth <= -1) {
    displayMonth = 11;
    incYear(-1,eltName);
  } else {
    newCalendar(eltName);
  }
}

function incYear(delta,eltName) {
  displayYear = parseInt(displayYear + '') + delta;
  newCalendar(eltName);
}

function makeDaysGrid(startDay,day,intDaysInMonth,newCal,eltName) {
   var daysGrid;
   var month = newCal.getMonth();
   var year = newCal.getFullYear();
   var isThisYear = (year == new Date().getFullYear());
   var isThisMonth = (day > -1)
   daysGrid = '<table border=1 cellspacing=0 cellpadding=2><tr><td bgcolor=#ffffff nowrap>';
   daysGrid += '<font face="courier new, courier" size=2>';
   daysGrid += '<a href="javascript:hideElement(\'' + eltName + '\')">x</a>';
   daysGrid += '&nbsp;&nbsp;';
   daysGrid += '<a href="javascript:incMonth(-1,\'' + eltName + '\')">&laquo; </a>';

   daysGrid += '<b>';
   if (isThisMonth) { daysGrid += '<font color=red>' + months[month] + '</font>'; }
   else { daysGrid += months[month]; }
   daysGrid += '</b>';

   daysGrid += '<a href="javascript:incMonth(1,\'' + eltName + '\')"> &raquo;</a>';
   daysGrid += '&nbsp;&nbsp;&nbsp;';
   daysGrid += '<a href="javascript:incYear(-1,\'' + eltName + '\')">&laquo; </a>';

   daysGrid += '<b>';
   if (isThisYear) { daysGrid += '<font color=red>' + year + '</font>'; }
   else { daysGrid += ''+year; }
   daysGrid += '</b>';

   daysGrid += '<a href="javascript:incYear(1,\'' + eltName + '\')"> &raquo;</a><br>';
   daysGrid += '&nbsp;Su Mo Tu We Th Fr Sa&nbsp;<br>&nbsp;';
   var dayOfMonthOfFirstSunday = (7 - startDay + 1);
   for (var intWeek = 0; intWeek < 6; intWeek++) {
      var dayOfMonth;
      for (var intDay = 0; intDay < 7; intDay++) {
        dayOfMonth = (intWeek * 7) + intDay + dayOfMonthOfFirstSunday - 7;
 if (dayOfMonth <= 0) {
          daysGrid += "&nbsp;&nbsp; ";
 } else if (dayOfMonth <= intDaysInMonth) {
   var color = "blue";
   if (day > 0 && day == dayOfMonth) color="red";
   daysGrid += '<a href="javascript:setDay(';
   daysGrid += dayOfMonth + ',\'' + eltName + '\')" '
   daysGrid += 'style="color:' + color + '">';
   var dayString = dayOfMonth + "</a> ";
   if (dayString.length == 6) dayString = '0' + dayString;
   daysGrid += dayString;
 }
      }
      if (dayOfMonth < intDaysInMonth) daysGrid += "<br>&nbsp;";
   }
   return daysGrid + "</td></tr></table>";
}

function setDay(day,eltName) {
  displayElement.value = (displayMonth + 1) + "/" + day + "/" + displayYear;
  displayElement.value = displayMonth + 1;
  if (displayElement.value.length == 1)
  		displayElement.value = "0" + (displayMonth + 1);
  if (day < 10)
  		displayElement.value += "/" + "0" + day + "/" + displayYear;
  else
  		displayElement.value += "/" + day + "/" + displayYear;
  hideElement(eltName);
}

function fixPosition(divname) {
 divstyle = getDivStyle(divname);
 positionerImgName = divname + 'Pos';
 isPlacedUnder = false;
 if (isPlacedUnder) {
  setPosition(divstyle,positionerImgName,true);
 } else {
  setPosition(divstyle,positionerImgName)
 }
}
function toggleDatePicker(eltName,formElt) {
  var x = formElt.indexOf('.');
  var formName = formElt.substring(0,x);
  var formEltName = formElt.substring(x+1);
  newCalendar(eltName,document.forms[formName].elements[formEltName]);
  toggleVisible(eltName);
}