public string[] GetMissingItems(string[] allItems, string[] someItems)
      {
         ArrayList missingItems = new ArrayList();
         for (int i=0; i<allItems.Length; i++)
         {
            bool match = false;
            if ( allItems[i].Trim().Length > 0 ) //filter out empty strings
            {
               for (int j=0; j<someItems.Length; j++)
               {
                  if ( someItems[j].Trim().Equals(allItems[i].Trim()) )
                  {
                     match = true;
                  }
               }
               if (!match)
               {
                  missingItems.Add(allItems[i]);
               }
            }
         }
         string[] aMissingItems = new string[missingItems.Count];
         missingItems.CopyTo(aMissingItems);

         return aMissingItems;
      }