var isNav4 = false, isNav5 = false, isIE4 = false
var strSeperator = "/"; 
var vDateType   = 3; 
var vYearType   = 4;  //Set to 2 or 4 for number of digits in the year for Netscape
var vYearLength = 4;	// 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;
	var whichCode = (window.Event) ? e.which : e.keyCode;
	// Check to see if a seperator is already present.
	// bypass the date if a seperator is present and the length greater than 8
	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 
	{
		//Create numeric string values for 0123456789/
		//The codes provided include both keyboard and keypad values
		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.\n\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.\n\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(0,2);
							var mDay = vDateName.value.substr(2,2);
							var mYear = vDateName.value.substr(4,4)
							vDateName.value = mMonth+strSeperator+mDay+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.\n\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.\n\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.\n\nPlease Re-Enter");
					vDateName.value = "";
					vDateName.focus();
					return true;
				}
				// Reformat date to format that can be validated. mm/dd/yyyy
				if (vDateValue.length >= 8 && dateCheck) 
				{
					// Additional date formats can be entered here and parsed out to
					// a valid date format that the validation routine will recognize.
					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.\n\nPlease Re-Enter");
							vDateName.value = "";
							vDateName.focus();
							return true;
						}
					}
					// Create temp. variable for storing the current vDateType
					var vDateTypeTemp = vDateType;
					// Change vDateType to a 1 for standard date format for validation Type will be changed back when validation is completed.
					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 == 1) // mm/dd/yyyy
							vDateName.value = mMonth+strSeperator+mDay+strSeperator+mYear;
						if (vDateTypeTemp == 3) // dd/mm/yyyy
							vDateName.value = mDay+strSeperator+mMonth+strSeperator+mYear;
					} 
					if (!dateValid(vDateValueCheck)) 
					{
						alert("Invalid Date.\n\nPlease Re-Enter");
						vDateType = vDateTypeTemp;
						vDateName.value = "";
						vDateName.focus();
						return true;
					}
					vDateType = vDateTypeTemp;
					return true;
				}
				else 
				{
					if (vDateType == 1) 
					{
						if (vDateValue.length == 2) 
							vDateName.value = vDateValue+strSeperator;
						if (vDateValue.length == 5) 
							vDateName.value = vDateValue+strSeperator;
					}
					if (vDateType == 2) 
					{
						if (vDateValue.length == 4) 
							vDateName.value = vDateValue+strSeperator;
						if (vDateValue.length == 7) 
							vDateName.value = vDateValue+strSeperator;
					} 
					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.\n\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 
			{
				
				strMonth = strDateArray[0];
				strDay = strDateArray[1];
				strYear = strDateArray[2];
			}
			booFound = true;
		}
	}
	if (booFound == false) 
	{
		if (strDate.length>5) 
		{
			strDay = strDate.substr(2, -2);
			strMonth = strDate.substr(0, 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;
}