c# substring find word

public static string getBetween(string strSource, string strStart, string strEnd)
{
    int Start, End;
    if (strSource.Contains(strStart) && strSource.Contains(strEnd))
    {
        Start = strSource.IndexOf(strStart, 0) + strStart.Length;
        End = strSource.IndexOf(strEnd, Start);
        return strSource.Substring(Start, End - Start);
    }
    else
    {
        return "";
    }
}

  public static string GetSubstring(string l_Source, string l_FindCharacter)
  {
    if (!l_Source.Contains(l_FindCharacter)) return string.Empty;
    int End = l_Source.IndexOf(l_FindCharacter, 0) + l_FindCharacter.Length;
    return l_Source.Substring(0, End - 1);
  }
//string l_Data = GetSubstring("100000.00", "."); //Test //100000