// Check browser version
var isNav4 = false, isNav5 = false, isIE4 = false
var strSeperator = "/"; 
var vDateType = 3; // Global value for type of date format
var vYearType = 4; //Set to 2 or 4 for number of digits in the year for Netscape
var vYearLength = 2; // Set to 4 if you want to force the user to enter 4 digits for the year before validating.
var err = 0; // Set the error code to a default of zero
if(navigator.appName == "Netscape") {
	if (navigator.appVersion < "5") {
		isNav4 = true;
		isNav5 = false;
	}
	else
	if (navigator.appVersion > "4") {
		isNav4 = false;
		isNav5 = true;
	}
}
else {
	isIE4 = true;
}
function DateFormat(vDateName, vDateValue, e, dateCheck, dateType) {
	vDateType = dateType;
	if (vDateValue == "~") {
		alert("AppVersion = "+navigator.appVersion+" \nNav. 4 Version = "+isNav4+" \nNav. 5 Version = "+isNav5+" \nIE Version = "+isIE4+" \nYear Type = "+vYearType+" \nDate Type = "+vDateType+" \nSeparator = "+strSeperator);
		vDateName.value = "";
		vDateName.focus();
		return true;
	}
	var whichCode = (window.Event) ? e.which : e.keyCode;
	if (vDateValue.length > 8 && isNav4) {
		if ((vDateValue.indexOf("-") >= 1) || (vDateValue.indexOf("/") >= 1))
			return true;
	}
	//Eliminate all the ASCII codes that are not valid
	var alphaCheck = " abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/-";
	if (alphaCheck.indexOf(vDateValue) >= 1) {
		if (isNav4) {
			vDateName.value = "";
			vDateName.focus();
			vDateName.select();
			return false;
		}
		else {
			vDateName.value = vDateName.value.substr(0, (vDateValue.length-1));
			return false;
		}
	}
	if (whichCode == 8) //Ignore the Netscape value for backspace. IE has no value
		return false;
	else {
		var strCheck = '47,48,49,50,51,52,53,54,55,56,57,58,59,95,96,97,98,99,100,101,102,103,104,105';
		if (strCheck.indexOf(whichCode) != -1) {
			if (isNav4) {
				if (((vDateValue.length < 6 && dateCheck) || (vDateValue.length == 7 && dateCheck)) && (vDateValue.length >=1)) {
					alert("Invalid Date\nPlease Re-Enter");
					vDateName.value = "";
					vDateName.focus();
					vDateName.select();
					return false;
				}
				if (vDateValue.length == 6 && dateCheck) {
					var mDay = vDateName.value.substr(2,2);
					var mMonth = vDateName.value.substr(0,2);
					var mYear = vDateName.value.substr(4,4);
					//Turn a two digit year into a 4 digit year
					if (mYear.length == 2 && vYearType == 4) {
						var mToday = new Date();
						//If the year is greater than 30 years from now use 19, otherwise use 20
						var checkYear = mToday.getFullYear() + 30; 
						var mCheckYear = '20' + mYear;
						if (mCheckYear >= checkYear)
							mYear = '19' + mYear;
						else
							mYear = '20' + mYear;
					}
					var vDateValueCheck = mMonth+strSeperator+mDay+strSeperator+mYear;
					if (!dateValid(vDateValueCheck)) {
						alert("Invalid Date\nPlease Re-Enter");
						vDateName.value = "";
						vDateName.focus();
						vDateName.select();
						return false;
					}
					return true;
				}
				else {
					// Reformat the date for validation and set date type to a 1
					if (vDateValue.length >= 8  && dateCheck) {
						if (vDateType == 3) // ddmmyyyy
						{
							var mMonth = vDateName.value.substr(2,2);
							var mDay = vDateName.value.substr(0,2);
							var mYear = vDateName.value.substr(4,4)
							vDateName.value = mDay+strSeperator+mMonth+strSeperator+mYear;
						}
						//Create a temporary variable for storing the DateType and change
						//the DateType to a 1 for validation.
						var vDateTypeTemp = vDateType;
						vDateType = 1;
						var vDateValueCheck = mMonth+strSeperator+mDay+strSeperator+mYear;
						if (!dateValid(vDateValueCheck)) {
							alert("Invalid Date\nPlease Re-Enter");
							vDateType = vDateTypeTemp;
							vDateName.value = "";
							vDateName.focus();
							vDateName.select();
							return false;
						}
						vDateType = vDateTypeTemp;
						return true;
					}
					else {
						if (((vDateValue.length < 8 && dateCheck) || (vDateValue.length == 9 && dateCheck)) && (vDateValue.length >=1)) {
							alert("Invalid Date\nPlease Re-Enter");
							vDateName.value = "";
							vDateName.focus();
							vDateName.select();
							return false;
						}
					}
				}
			}
			else {
				// Non isNav Check
				if (((vDateValue.length < 8 && dateCheck) || (vDateValue.length == 9 && dateCheck)) && (vDateValue.length >=1)) {
					alert("Invalid Date\nPlease Re-Enter");
					vDateName.value = "";
					vDateName.focus();
					return true;
				}
				if (vDateValue.length >= 8 && dateCheck) {
					if (vDateType == 3) // dd/mm/yyyy
					{
						var mDay = vDateName.value.substr(0,2);
						var mMonth = vDateName.value.substr(3,2);
						var mYear = vDateName.value.substr(6,4)
					}
					if (vYearLength == 4) {
						if (mYear.length < 4) {
							alert("Invalid Date\nPlease Re-Enter");
							vDateName.value = "";
							vDateName.focus();
							return true;
						}
					}
					var vDateTypeTemp = vDateType;
					vDateType = 1;
					// Store reformatted date to new variable for validation.
					var vDateValueCheck = mMonth+strSeperator+mDay+strSeperator+mYear;
					if (mYear.length == 2 && vYearType == 4 && dateCheck) {
						//Turn a two digit year into a 4 digit year
						var mToday = new Date();
						//If the year is greater than 30 years from now use 19, otherwise use 20
						var checkYear = mToday.getFullYear() + 30; 
						var mCheckYear = '20' + mYear;
						if (mCheckYear >= checkYear)
							mYear = '19' + mYear;
						else
							mYear = '20' + mYear;
						vDateValueCheck = mMonth+strSeperator+mDay+strSeperator+mYear;
						// Store the new value back to the field.  This function will
						// not work with date type of 2 since the year is entered first.
						if (vDateTypeTemp == 3) // dd/mm/yyyy
							vDateName.value = mDay+strSeperator+mMonth+strSeperator+mYear;
					} 
					if (!dateValid(vDateValueCheck)) {
						alert("Invalid Date\nPlease Re-Enter");
						vDateType = vDateTypeTemp;
						vDateName.value = "";
						vDateName.focus();
						return true;
					}
					vDateType = vDateTypeTemp;
					return true;
				}
				else {
					if (vDateType == 3) {
						if (vDateValue.length == 2) {
							vDateName.value = vDateValue+strSeperator;
						}
						if (vDateValue.length == 5) {
							vDateName.value = vDateValue+strSeperator;
						}
					}
					return true;
				}
			}
			if (vDateValue.length == 10&& dateCheck) {
				if (!dateValid(vDateName)) {
					// Un-comment the next line of code for debugging the dateValid() function error messages
					//alert(err);  
					alert("Invalid Date\nPlease Re-Enter");
					vDateName.focus();
					vDateName.select();
				}
			}
			return false;
		}
		else {
			// If the value is not in the string return the string minus the last
			// key entered.
			if (isNav4) {
				vDateName.value = "";
				vDateName.focus();
				vDateName.select();
				return false;
			}
			else
			{
				//vDateName.value = vDateName.value.substr(0, (vDateValue.length-1));
				return false;
			}
		}
	}
}
function dateValid(objName) {
	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";
	//strDate = datefield.value;
	strDate = objName;
	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);
		}
	}
	//Adjustment for short years entered
	if (strYear.length == 2) {
		strYear = '20' + strYear;
	}
	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;
			}
		}
	}
	return true;
}
function LeapYear(intYear) {
	if (intYear % 100 == 0) {
		if (intYear % 400 == 0) { return true; }
	}
	else {
		if ((intYear % 4) == 0) { return true; }
	}
	return false;
}
//  End -->




function isValidDate(dateStr) {

var mmddyyyy;

// Checks for the following valid date formats:
// DD/MM/YY    DD-MM-YYYY

datePat = /^(\d{1,2})(\/|-)(\d{1,2})\2(\d{4})$/; // requires 4 digit year

var matchArray = dateStr.match(datePat); // is the format ok?
//if (matchArray == null) {
//alert(dateStr + " Date is not in a valid format.");
//return false;
//}

day = matchArray[1]; // parse date into variables
month = matchArray[3];
year = matchArray[4];


if (month < 1 || month > 12) { // check month range
alert("Month must be between 1 and 12.");
return false;
}
if (day < 1 || day > 31) {
alert("Day must be between 1 and 31.");
return false;
}
if ((month==4 || month==6 || month==9 || month==11) && day==31) {
alert("Month "+month+" doesn't have 31 days!")
return false;
}
if (month == 2) { // check for february 29th
var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
if (day>29 || (day==29 && !isleap)) {
alert("February " + year + " doesn't have " + day + " days!");
return false;
   }
}
mmddyyyy =  month + "/"+ day +"/"+ year;

return mmddyyyy;
}


function dateDiff(dateform,firstdate,seconddate,diff) {

date1 = new Date();
date2 = new Date();
diff  = new Date();

var d1;
var d2;

//d1=isValidDate(dateform.firstdate.value);
//d2=isValidDate(dateform.seconddate.value);


d1=isValidDate(firstdate.value);
d2=isValidDate(seconddate.value);


if (d1) 
   { // Validates first date 
   date1temp = new Date(d1);
   date1.setTime(date1temp.getTime());
   //alert ("date1  :" + date1temp);
 }
else return false; // otherwise exits


if (d2) 
  { // Validates second date 
   date2temp = new Date(d2);
   date2.setTime(date2temp.getTime());
  // alert ("date2  :" + date2temp);
  }
else return false; // otherwise exits

// sets difference date to difference of first date and second date

if (date2 >= date1) {

diff.setTime(Math.abs(date1.getTime() - date2.getTime()));

timediff = diff.getTime();

weeks = Math.floor(timediff / (1000 * 60 * 60 * 24 * 7));
timediff -= weeks * (1000 * 60 * 60 * 24 * 7);

days = Math.floor(timediff / (1000 * 60 * 60 * 24)); 
timediff -= days * (1000 * 60 * 60 * 24);

hours = Math.floor(timediff / (1000 * 60 * 60)); 
timediff -= hours * (1000 * 60 * 60);

mins = Math.floor(timediff / (1000 * 60)); 
timediff -= mins * (1000 * 60);

secs = Math.floor(timediff / 1000); 
timediff -= secs * 1000;

//dateform.difference.value = weeks  + " weeks, " + days + " days, " + hours + " hours, " + mins + " minutes, and " + secs + " seconds";
diff = weeks *7  +  days +1 ;
return diff;
}
else
{
  alert("Invalid To Date");
  dateform.seconddate.focus();
  dateform.difference.value="";
 }

 // form should never submit, returns false
}
//  End -->