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 : dd/mm/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 checkDate(mytxtDate) 
{
	var myDate=mytxtDate.value
	//alert(myDate);
    var tmpDate="";
    var yR ="";
    var dateLen =0;
	
    if(myDate=="") return false;//return false;
	
    tmpDate = removeSC(myDate, ".");
    tmpDate = removeSC(tmpDate, "-");
    tmpDate = removeSC(tmpDate, "/");

	dateLen =tmpDate.length;
	
	if (dateLen == 3 )
	{
		yR = "/200"+tmpDate.substr(2, 1);
	}
	else if (dateLen == 8 )
	{
		yR = "/" +tmpDate.substr(4, 4);
	}
	else if (dateLen == 7 )
	{
		yR = "/"+tmpDate.substr(3, 4);
	}
	else
	{
		if (tmpDate.substr(tmpDate.length-2, 2) > 50)
			yR = "/19"+tmpDate.substr(tmpDate.length-2 ,2);
		else
			yR = "/20"+tmpDate.substr(tmpDate.length-2 ,2);
	}   

	switch (dateLen)
	{
		case 3:
			tmpDate = "0"+tmpDate.substr(0,1)+"/0"+tmpDate.substr(1, 1)+yR;
			break;
		case 4:
			tmpDate = "0"+tmpDate.substr(0, 1)+"/0"+tmpDate.substr(1, 1)+yR;
			break;
		case 5:
		case 7:
			if (tmpDate.substr(2, 1) > 12 )
				tmpDate = tmpDate.substr(0, 2)+"/0"+tmpDate.substr(2, 1)+yR;
			else
				tmpDate ="0"+tmpDate.substr(0, 1)+"/"+tmpDate.substr(1, 2)+yR;
			break;	
		case 6:
			tmpDate =tmpDate.substr(0, 2)+"/"+tmpDate.substr(2, 2)+yR;
			break;
		case 8:
			tmpDate = tmpDate.substr(0, 2)+"/"+tmpDate.substr( 2, 2)+yR;
			break;
	}
	if (isDate(tmpDate))
	{
		mytxtDate.value=tmpDate;
		return true;
	}
	else
	{
		mytxtDate.focus();
		mytxtDate.value="";
		return false;
	} 			
}

function removeSC(myDate , SC)
{
   	var myArr="";
    var i=0;
	var myTmp ="";
    myTmp = "";
    myArr = myDate.split(SC);
    if (myArr.length > 1 )
	{
        for (i = 0; i <= myArr.length-1; i++ )
		{
			if ((myArr[i].length) == 1 )
			{
                myTmp = myTmp.concat("0",myArr[i]);
			}
            else if (myArr[i].length == 3 || myArr[i].length == 5 || myArr[i].length == 6) 
			{
                myTmp = myTmp.concat("0",myArr[i]);
			}
            else
			{
                myTmp = myTmp.concat(myArr[i]);
			}
		}
		return myTmp;
	}
    else
	{
		return myDate;
	}
}