public void populateDateDrop(string DateType, DropDownList DropListObject)
{
  DateTimeFormatInfo dateFormating = new DateTimeFormatInfo();

  DropListObject.Items.Insert(0, new ListItem("", ""));

  switch(DateType)
  {
    case "day":
      for (int day=1; day<=31; day++)
      {
       DropListObject.Items.Insert(
           day, 
           new ListItem(day.ToString(), day.ToString())
		   );
      }
      break;
    case "month":
      for (int month=1; month<=12; month++)
      {
      DropListObject.Items.Insert(
         month,
         new ListItem(dateFormating.GetMonthName(month),month.ToString())
         );
      }
      break;
    case "year":
      for (int year=1; year<=35; year++)
      {
      DropListObject.Items.Insert(
         year, 
         new ListItem((year+1984).ToString(), (year+1984).ToString())
         );
      }
      break;
    }
}

populateDateDrop("day", droplistob);
populateDateDrop("month", droplistob);
populateDateDrop("year", droplistob);