// Declaring valid date character, minimum year and maximum year
var dtCh= "/";
var minYear=1900;
var maxYear=2100;

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to 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 strDay=dtStr.substring(0,pos1)
	var strMonth=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 (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
}

// If the Date field isn't a number or then set to DD, MM, YY on blur
function resetDate(field,display)
{
	if (isNaN(field.value)==true || field.value=="")
	{
		field.value=display
	}
}

// Clears the date field on focus if it is DD, MM, or YY
function setDate(field)
{
	if (isNaN(field.value)==true)
	{
		field.value=""
	}
}

// Auto Tab
var isNN = (navigator.appName.indexOf("Netscape")!=-1);

function autoTab(input,len, e)
	{
		var keyCode = (isNN) ? e.which : e.keyCode; 
		var filter = (isNN) ? [0,8,9] : [0,8,9,16,17,18,37,38,39,40,46];
		if(input.value.length >= len && !containsElement(filter,keyCode))
			{
				input.value = input.value.slice(0, len);
				input.form[(getIndex(input)+1) % input.form.length].focus();
			}

	function containsElement(arr, ele) {
		var found = false, index = 0;
		while(!found && index < arr.length)
		if(arr[index] == ele)
		found = true;
		else
		index++;
		return found;
}
function getIndex(input)
	{
		var index = -1, i = 0, found = false;
		while (i < input.form.length && index == -1)
		if (input.form[i] == input)index = i;
		else i++;
		return index;
	}
return true;
}