// Date Validation library

function CheckDate(objName,FieldName) {
  var datefield = objName;
  if (chkdate(objName) == false) {
    datefield.select();
    alert("That date is not valid. "+
	  "Examples of valid dates include 3-feb-2001, 03-Feb-01, 3/2/2001. The year must also be greater than 1980");
    datefield.focus();
    return false;
  } else {
    return true;
  }
}
function chkdate(objName) {
  //var strDatestyle = "US"; //United States date style
  var strDatestyle = "EU";  //European date style
  var strDate;
  var strDateArray;
  var strDay;
  var strMonth;
  var strYear;
  var intday;
  var intMonth;
  var intYear;
  var booFound = false;
  var datefield = objName;
  var strSeparatorArray = new Array("-"," ","/",".");
  var intElementNr;
  var err = 0;
  var strMonthArray = new Array(12);
  strMonthArray[0] = "Jan";
  strMonthArray[1] = "Feb";
  strMonthArray[2] = "Mar";
  strMonthArray[3] = "Apr";
  strMonthArray[4] = "May";
  strMonthArray[5] = "Jun";
  strMonthArray[6] = "Jul";
  strMonthArray[7] = "Aug";
  strMonthArray[8] = "Sep";
  strMonthArray[9] = "Oct";
  strMonthArray[10] = "Nov";
  strMonthArray[11] = "Dec";
  strDayArray = new Array("01","02","03","04","05","06","07","08","09","10",
			  "11","12","13","14","15","16","17","18","19","20",
			  "21","22","23","24","25","26","27","28","29","30",
			  "31");
  strDate = datefield.value;
  if (strDate.length < 1) {
    return true;
  }
  for (intElementNr = 0; intElementNr < strSeparatorArray.length; 
       intElementNr++) {
    if (strDate.indexOf(strSeparatorArray[intElementNr]) != -1) {
      strDateArray = strDate.split(strSeparatorArray[intElementNr]);
      if (strDateArray.length != 3) {
	err = 1;
	return false;
      } else {
	strDay = strDateArray[0];
	strMonth = strDateArray[1];
	strYear = strDateArray[2];
      }
      booFound = true;
    }
  }
  if (booFound == false) {
    if (strDate.length>5) {
      strDay = strDate.substr(0, 2);
      strMonth = strDate.substr(2, 2);
      strYear = strDate.substr(4);
    } else {
      return false;
    }
  }
  if (strYear.length == 2) {
    strYear = '20' + strYear;
  }
  if(strYear<1980) { return false };
  // US style
  if (strDatestyle == "US") {
    strTemp = strDay;
    strDay = strMonth;
    strMonth = strTemp;
  }
  intday = parseInt(strDay, 10);
  if (isNaN(intday)) {
    err = 2;
    return false;
  }
  intMonth = parseInt(strMonth, 10);
  if (isNaN(intMonth)) {
    for (i = 0;i<12;i++) {
      if (strMonth.toUpperCase() == strMonthArray[i].toUpperCase()) {
	intMonth = i+1;
	strMonth = strMonthArray[i];
	i = 12;
      }
    }
    if (isNaN(intMonth)) {
      err = 3;
      return false;
    }
  }
  intYear = parseInt(strYear, 10);
  if (isNaN(intYear)) {
    err = 4;
    return false;
  }
  if (intMonth>12 || intMonth<1) {
    err = 5;
    return false;
  }
  if ((intMonth == 1 || intMonth == 3 || intMonth == 5 || 
       intMonth == 7 || intMonth == 8 || intMonth == 10 || 
       intMonth == 12) && (intday > 31 || intday < 1)) {
    err = 6;
    return false;
  }
  if ((intMonth == 4 || intMonth == 6 || intMonth == 9 || 
       intMonth == 11) && (intday > 30 || intday < 1)) {
    err = 7;
    return false;
  }
  if (intMonth == 2) {
    if (intday < 1) {
      err = 8;
      return false;
    }
    if (LeapYear(intYear) == true) {
      if (intday > 29) {
	err = 9;
	return false;
      }
    } else {
      if (intday > 28) {
	err = 10;
	return false;
      }
    }
  }
  if (strDatestyle == "US") {
    datefield.value = strMonthArray[intMonth-1] + "-" + strDayArray[intday-1] +
      "-" + strYear;
  } else {
    datefield.value = strDayArray[intday-1] + "-" + strMonthArray[intMonth-1] +
      "-" + strYear;
  }
  return true;
}
function LeapYear(intYear) {
  if (intYear % 100 == 0) {
    if (intYear % 400 == 0) { return true; }
  } else {
    if ((intYear % 4) == 0) { return true; }
  }
  return false;
}

function doDateCheck(from, to,NameFrom,NameTo) {
  var date_from = from.value;
  var date_to   = to.value;
  date_from = date_from.replace(/-/g," ");
  date_to   = date_to.replace(/-/g," ");
  //alert(date_from+' '+date_to);
  if (Date.parse(date_from) <= Date.parse(date_to)) {
    return true;
  } else {
    if (from.value == "" || to.value == "") {
      alert("Both the "+NameTo+" and "+NameFrom+" dates must be entered.");
      return false;
    } else {
      alert("The "+NameTo+" must occur after the "+NameFrom);
      return false;
    }
  }
}