/**
 * DHTML date validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */

// declare min/max age for DOB
var minAge = 21;
var maxAge = 70;
 
// Declaring valid date character, minimum year and maximum year
var dtCh= "/";

var d = new Date();
var minYear=d.getFullYear()-(maxAge+1);
var maxYear=d.getFullYear()-minAge;

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 errormsg = "";
	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 (pos1==-1 || pos2==-1){
		errormsg += "The date format should be : mm/dd/yyyy\n";
	}
	if (strMonth.length<1 || month<1 || month>12){
		errormsg += "Please enter a valid month\n";
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		errormsg += "Please enter a valid day\n";
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		errormsg += "Please enter a valid date\n";
	}
	
	return errormsg;
}

function isValidBirth(dtStr){ 
	var errormsg = isDate(dtStr)
		
	//  custom Date of Birth range check
	var dobDate=new Date();
	dobDate.setFullYear(year,month-1,day);
	dobDate.setHours(0,0,0,0);

	var firstDate=new Date(); // day prior to 71 birthday
	firstDate.setFullYear(minYear,firstDate.getMonth(),firstDate.getDate()+1);
	firstDate.setHours(0,0,0,0);

	var lastDate=new Date(); // 21 year birthday
	lastDate.setFullYear(maxYear,lastDate.getMonth(),lastDate.getDate());
	lastDate.setHours(0,0,0,0);

	if (strYr.length != 4 || year==0 || year<minYear || year>maxYear){
		errormsg += "Please enter a valid 4 digit year between "+minYear+" and "+maxYear+"\n";
	}

	if (dobDate < firstDate || dobDate > lastDate){ 
		errormsg += "Purchaser must be between " + minAge + " and " + maxAge + " years old.\nDate of Birth must be between: "+
			(firstDate.getMonth()+1)+"/"+firstDate.getDate()+"/"+firstDate.getFullYear()
			+" and "+
			(lastDate.getMonth()+1)+"/"+lastDate.getDate()+"/"+lastDate.getFullYear() + "\n";
	}
	
	if(errormsg) {
		alert("Date of Birth Error: " + dtStr + "\n" + errormsg);
		return false;
	}

return true;
}

function isNotExpired(dtStr) {
	var errormsg = isDate(dtStr)

	var licexpDate=new Date();
	licexpDate.setFullYear(year,month-1,day);
	licexpDate.setHours(0,0,0,0);

	d.setHours(0,0,0,0);

	if (licexpDate < d ){ 
		errormsg += "License not valid/has expired\n";
	}

	if(errormsg) {
		alert("License Expiration Error: " + dtStr + "\n" + errormsg);
		return false;
	}

return true;
}