substring.cs

      // Return the text found between two other substrings.
      public static string Substring(this string src, string startStr, string finishStr)
      {
         string substr = "";

         int atStart = src.IndexOf(startStr);
         if (atStart >= 0)
         {
            int afterStart = atStart + startStr.Length;
            int atFinish = src.IndexOf(finishStr, afterStart);

            if (atFinish >= 0)
            {
               substr = src.Substring(afterStart, atFinish - afterStart);
            }
         }

         return substr;
      }