// <Snippet14>
using System;

[assembly: CLSCompliant(true)]

public class ErrorClass : Exception
{
   string msg;

   public ErrorClass(string errorMessage)
   {
      msg = errorMessage;
   }

   public override string Message
   {
      get { return msg; }
   }
}

public static class StringUtilities
{
   public static string[] SplitString(this string value, int index)
   {
      if (index < 0 | index > value.Length) {
         ErrorClass badIndex = new ErrorClass("The index is not within the string.");
         throw badIndex;
      }
      string[] retVal = { value.Substring(0, index - 1),
                          value.Substring(index) };
      return retVal;
   }
}
// </Snippet14>

public class Example
{
   public static void Main()
   {
   }
}