/// <summary>
/// Extracts a string from between a pair of delimiters. Only the first 
/// instance is found.
/// </summary>
/// <param name="source">Input String to work on</param>
/// <param name="StartDelim">Beginning delimiter</param>
/// <param name="endDelim">ending delimiter</param>
/// <param name="CaseInsensitive">Determines whether the search for delimiters is case sensitive</param>
/// <returns>Extracted string or ""</returns>
public static string ExtractString(string source, string beginDelim,