用javascript比较日期

用javascript比较日期，

   function compareDate(DateOne,DateTwo){
         var OneMonth = DateOne.substring(5,DateOne.lastIndexOf ("-"));
         var OneDay = DateOne.substring(DateOne.length,DateOne.lastIndexOf ("-")+1);
         var OneYear = DateOne.substring(0,DateOne.indexOf ("-"));
       
         var TwoMonth = DateTwo.substring(5,DateTwo.lastIndexOf ("-"));
         var TwoDay = DateTwo.substring(DateTwo.length,DateTwo.lastIndexOf ("-")+1);
         var TwoYear = DateTwo.substring(0,DateTwo.indexOf ("-"));
       
         if (Date.parse(OneMonth+"/"+OneDay+"/"+OneYear) >= Date.parse(TwoMonth+"/"+TwoDay+"/"+TwoYear)){
         return true;
         }else{
         return false;
         }
     }

/*目前只支持年－月－日这样的格式*/