function Ovul()
{
form1 = document.forms["OvulD"];
year = form1.Year.options[form1.Year.selectedIndex].value;
month = form1.Month.options[form1.Month.selectedIndex].value;
day = form1.Day.options[form1.Day.selectedIndex].value;
if (form1.duration[0].checked)
		{duration = 28; add = 14;}
	else 
		{duration = 30; add = 16 ;}
	if(!(ValidateDate(month,year,day,form1)))
	{
		alert("Invalid Date , Day Of Month Is Not Right ,TRY AGAIN ");
		return;
	}
if(!(ValidateDate(month,year,day,form1)))
{
alert("Invalid Date , Day Of Month Is Not Right ,TRY AGAIN ");
return;
}
}

function ValidateDate(month,year,day,form1)
 {
	var lmonth,lyear,lday;
	
	lmonth = parseInt(" " + month);
	lyear = parseInt(" " + year);
	lday = parseInt(" " + day);
	ldays = DaysInMonth(lmonth,lyear);
	if (lday > ldays) 
	{
	return false;
	} 
	else 
	{
	daysl = ldays - lday;
	OvulDate(lmonth,lyear,lday,daysl,form1);  
	return true;
	}
}

function DaysInMonth(month,year) 
{
	var days;
    if((month==1)||(month==3)||(month==5)||(month==7)||(month==8)||(month==10)||(month==12))
		days=31;
	else if((month==4)||(month==6)||(month==9)||(month==11))
       days = 30;
	else 	  		
	{
		if (IsLeapYear(year))
		 {
			days=29;
		}
		else
		{
			days=28;
		}
	 }
	
	return days;


}

function IsLeapYear(lyear)  
{
	if ( (lyear%4 == 0 && lyear%100 != 0) || (lyear%400 == 0) ) 
	{
		return true;
	}
	else 
	{
		 return false;
	}
}

function OvulDate(month,year,day,daysl,form1)
{
var month2,year2,day2;
year2=year;
month2=month;
if(daysl < add )
{
month2 = month + 1;
var d1 = add - daysl;
day2 = d1;
} 
else
{
day2 = day + add ;
}
if (month2>12)
{
  month2 = 1;
  year2 = year+1;
}


var dd = new Date();
dd.setMonth(month2 - 1);
dd.setDate(day2);
dd.setYear(year2);
var dd1 = dd.toGMTString();
var n = dd1.length;
dd2 = dd1.slice(0,n-12);
form1.display.value = dd2;
return;
}