public void MoveToStart(object source)
 {
     if (TypeUtilities.IsNumeric(source))
     {
         m_excelWorksheets.MoveToStart(TypeConverter.ToInteger(source));
     }
     else if (TypeUtilities.IsString(source))
     {
         m_excelWorksheets.MoveToStart(TypeConverter.ToString(source));
     }
     else
     {
         throw new JavaScriptException(this.Engine, "Error", "Could not move worksheet -- did not understand the argument type.");
     }
 }