public boolean isMonthLetter(String letter)
    {
         boolean validLetter = false;

         if(letter.equals("J"))
         {
             validLetter = true;
         }
         else if(letter.equals("A"))
         {
             validLetter = true;
         }
         else if(letter.equals("M"))
         {
             validLetter = true;
         }
         else if(letter.equals("D"))
         {
             validLetter = true;
         }
         else if(letter.equals("F"))
         {
             validLetter = true;
         }
         else if(letter.equals("N"))
         {
             validLetter = true;
         }
         else if(letter.equals("O"))
         {
             validLetter = true;
         }
         else if(letter.equals("S"))
         {
             validLetter = true;
         }

         return validLetter;
     }