// JavaScript Document

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,fname){
	var todaydate = new Date();	
	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")
		document.getElementById(fname).value="DD/MM/YYYY";
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		 if(isNaN(month)){
			 alert("The date format should be : DD/MM/YYYY");
			 document.getElementById(fname).focus();
		 }else{
		alert("Please enter a valid month")
		 document.getElementById(fname).focus();
		 }
		return false
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert("Please enter a valid day")
		 document.getElementById(fname).focus();
		return false
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		alert("Please enter a valid 4 digit year from "+todaydate.getYear())
		 document.getElementById(fname).focus();
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		alert("Please enter a valid date")
		 document.getElementById(fname).focus();
		return false
	}
return true
}

function ValidateForm(id,fname){
	    
		if (isDate(id,fname)==false){
			document.getElementById(fname).focus();
			document.getElementById(fname).value="DD/MM/YYYY";
					return false
	}
    return true
 }


function getDateObj_CurrentDate(){
    var input= new Date();
	var dayfield=input.getDate();
    var monthfield=input.getMonth();
	var yearfield=input.getFullYear();
	var months = new Array("0","1","2","3","4","5","6","7","8","9","10","11");
		
	switch(monthfield){	
		case 0: monthfield = "01";	
			  break;			 
		case 1: monthfield = "02";
			  break;
		case 2: monthfield = "03";
			  break;
		case 3: monthfield = "04";
			  break;
		case 4: monthfield = "05";
			  break;
		case 5: monthfield = "06";
			  break;
		case 6: monthfield = "07";
			  break;
		case 7: monthfield = "08";
			  break;
		case 8: monthfield = "09";
			  break;
		case 9: monthfield = "10";
			  break;
		case 10: monthfield = "11";
			  break;
		case 11: monthfield = "12";
			  break;
	}	
	switch(dayfield){	
		case 1: dayfield = "01";	
			  break;			 
		case 2: dayfield = "02";
			  break;
		case 3: dayfield = "03";
			  break;
		case 4: dayfield = "04";
			  break;
		case 5: dayfield = "05";
			  break;
		case 6: dayfield = "06";
			  break;
		case 7: dayfield = "07";
			  break;
		case 8: dayfield = "08";
			  break;
		case 9: dayfield = "09";
			  break;

	}	
	var dayobj = dayfield+"/"+monthfield+"/"+yearfield;
    return dayobj;
}


/* function to calculate the number of days between two given dates */

function daysBetween(date1, date2){ 
//alert(date1);
   if (date1.indexOf("-") != -1) { date1 = date1.split("-"); } else if (date1.indexOf("/") != -1) { date1 = date1.split("/"); } else { return 0; } 
   if (date2.indexOf("-") != -1) { date2 = date2.split("-"); } else if (date2.indexOf("/") != -1) { date2 = date2.split("/"); } else { return 0; } 
   if (parseInt(date1[1], 10) >= 1000) { 
       var sDate = new Date(date1[1]+"/"+date1[0]+"/"+date1[2]); 
   } else if (parseInt(date1[2], 10) >= 1000) { 
       var sDate = new Date(date1[2]+"/"+date1[1]+"/"+date1[0]); 
   } else { 
       return 0; 
   } 
   if (parseInt(date2[1], 10) >= 1000) { 
       var eDate = new Date(date2[1]+"/"+date2[0]+"/"+date2[2]); 
   } else if (parseInt(date2[2], 10) >= 1000) { 
       var eDate = new Date(date2[2]+"/"+date2[1]+"/"+date2[0]); 
   } else { 
       return 0; 
   } 
   var one_day = 1000*60*60*24; 
   var daysApart = Math.abs(Math.ceil((sDate.getTime()-eDate.getTime())/one_day)); 
   return daysApart; 
} 


function minMaxDaysValueFunction(text1,text2,textfieldname){
	var feild1 =ValidateForm(document.getElementById(text1).value,text1);
	var feild2 =ValidateForm(document.getElementById(text2).value,text2);
	if((feild1==true)&&(feild2==true)){
	document.getElementById(textfieldname).value=daysBetween(document.getElementById(text1).value, document.getElementById(text2).value);
	}
}

function changeDefaultValue(text1,text2,text3,text4){
	document.getElementById(text1).value="DD/MM/YYYY";
	document.getElementById(text2).value="DD/MM/YYYY";
	document.getElementById(text3).value=""
	document.getElementById(text4).value=""
	resetDates();
}
/*
var datefieldValue ;
function passDateValueToReturnTextField(textfield){
	 datefieldValue = document.getElementById(textfield).value;
	if(datefieldValue=="DD/MM/YYYY"){
		alert(datefieldValue);
		datefieldValue=getDateObj_CurrentDate();
	}
	else{
		alert(datefieldValue+"in else");
		datefieldValue=datefieldValue;
	}
}*/