js 比较2日期大小

//比较2日期大小
   function isStartEndDate(startDate,endDate){  
                //alert(startDate+"==="+endDate);  
                if(startDate.length>0&&endDate.length>0){  
                    var startDateTemp = startDate.split(" ");  
                    var endDateTemp = endDate.split(" ");  
                    var arrStartDate = startDateTemp[0].split("-");  
                    var arrEndDate = endDateTemp[0].split("-");  
                   if(parseInt(arrStartDate[0])>parseInt(arrEndDate[0]))
                    return false;
                   else
                    if(parseInt(arrStartDate[0])==parseInt(arrEndDate[0]))
                   {
                          if(parseInt(arrStartDate[1])>parseInt(arrEndDate[1]))
                          return false;
                           else
                           if(parseInt(arrStartDate[1])==parseInt(arrEndDate[1]))
                           {
                                   if(parseInt(arrStartDate[2])>parseInt(arrEndDate[2]))
                                   return false;
                                   else
                                   return true;
                           }
                           else return true;
                   }
                   else return true;
                  
                 }
                 else
                  return false;
            }