var MonHead = new Array(12); 
			MonHead[0] = 31; MonHead[1] = 28; MonHead[2] = 31; MonHead[3] = 30; MonHead[4]  = 31; MonHead[5]  = 30; 
			MonHead[6] = 31; MonHead[7] = 31; MonHead[8] = 30; MonHead[9] = 31; MonHead[10] = 30; MonHead[11] = 31; 
				
		function IsPinYear(year)
		{ 
			if (0==year%4&&((year%100!=0)||(year%400==0))) return 1;else return 0; 
		} 
		function GetMonthCount(year,month)  
		{ 
			var c=MonHead[month-1];if((month==2)&&IsPinYear(year)) c++;return c; 
		} 
				
		
		function AddDay(yearObj,monthObj,dayObj)  
		{ 
		    
			var yearVal=yearObj.options[yearObj.options.selectedIndex].value;
			var monthVal=monthObj.options[monthObj.options.selectedIndex].value;
			var dayVal=dayObj.options[dayObj.options.selectedIndex].value;
			
			var Feb=2;
			var MaxDay=MonHead[monthVal-1];
			
			if(monthVal==Feb)
			{ 
			 	
			 	var isleapyear=IsPinYear(yearVal);
			 	if (isleapyear>0)	
			 	    MaxDay=29;
			 	else
			 	    MaxDay=28;
			}
			
			removeAll(dayObj);
			for (i = 1; i < MaxDay+1; i++) 
			{
				dayObj.options.add(new Option (i,i));
			}  
			dayObj.value=dayVal;
			if (dayObj.value<'1') dayObj.value=1;
        }   
        
		function removeAll(obj)
		{
			var len=obj.length;
			for(var i=len-1;i>=0;i--)
			{      
				obj.remove(i);  
			}
		}