var dtCh= "/";
var minYear=1900;
var maxYear=2100;

function isInteger(s)  // All characters are numbers
	{
	var i;
	for (i = 0; i < s.length; i++)
		{   
		var c = s.charAt(i);
		if (((c < "0") || (c > "9")))
			return false;
		}
	return true;
	}
function stripCharsInBag(s, bag)  // Search through string one character at a time; If character is not in bag, append to returnString
	{
	var i;
	var returnString = "";
	for (i = 0; i < s.length; i++)
		{   
		var c = s.charAt(i);
		if (bag.indexOf(c) == -1)
			returnString += c;
		}
	return returnString;
	}
function daysInFebruary (year) // February has 29 days in any year evenly divisible by four, EXCEPT for centurial years which are not also divisible by 400
	{
	    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
	}
function DaysArray(n)
	{
	for (var i = 1; i <= n; i++)
		{
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11)
			{this[i] = 30}
		if (i==2)
			{this[i] = 29}
		} 
	return this;
	}

function isDate(dtStr)
	{
	var daysInMonth = DaysArray(12)
	var pos1=dtStr.indexOf(dtCh)
	var pos2=dtStr.indexOf(dtCh,pos1+1)
	var strMonth=dtStr.substring(0,pos1)
	var strDay=dtStr.substring(pos1+1,pos2)
	var strYear=dtStr.substring(pos2+1)
	strYr = strYear
	if (strDay.charAt(0)=="0" && strDay.length>1)
		strDay=strDay.substring(1)
	if (strMonth.charAt(0)=="0" && strMonth.length>1)
		strMonth=strMonth.substring(1)
	for (var i = 1; i <= 3; i++)
		{
		if (strYr.charAt(0)=="0" && strYr.length>1)
			strYr=strYr.substring(1)
		}
	month = parseInt(strMonth)
	day = parseInt(strDay)
	year = parseInt(strYr)

	if (dtStr.length > 0)
		{
		if (pos1==-1 || pos2==-1)
			{
			alert("The date format should be : mm/dd/yyyy");
			return false;
			}
		if (strMonth.length<1 || month<1 || month>12)
			{
			alert("Please enter a valid month");
			return false;
			}
		if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month])
			{
			alert("Please enter a valid day");
			return false;
			}
		if (strYear.length != 4 || year==0 || year<minYear || year>maxYear)
			{
			alert("Please enter a valid 4 digit year between "+minYear+" and "+maxYear);
			return false;
			}
		if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false)
			{
			alert("Please enter a valid date");
			return false;
			}
		}
	return true
	}
function DateX(InputName)
	{
	InputValue = InputName.value;
	if (isDate(InputValue) == false)
		{
		InputName.focus();
		InputName.select();
		//return false;
		}
	return true;
 	}