public void GeFilesSrez(string dbname,
               Boolean CheckIncludeMask, string mask1,                          //Включение по маске
               Boolean CheckExcludeMask, string mask2,                          //Исключение по маске
               Boolean CheckCreation, DateTime Cr_start, DateTime Cr_End,       //Дата создания
               Boolean CheckAccess, DateTime Ac_start, DateTime Ac_End,         //Дата доступа
               Boolean CheckChange, DateTime Ch_start, DateTime Ch_End,         //Дата изменения
               Boolean CheckHidden,                                             //Скрытый
               Boolean ChechOnlyRead,                                           //Только чтение
               Boolean CheckEncrypt                                             //Зашифрован
               
            )
          {    
            string CS = @"Data Source=" + setup.AppDir + @"Data\" + dbname + ".sdf;Persist Security Info=False;";
            SqlCeConnection con = new SqlCeConnection(CS);
            no_result_query("TRUNCATE Files",con);
            
            string sql = "SELECT * FROM Files Where ";
            if (CheckIncludeMask) sql += "NAME LIKE '%" + mask1 + "%' AND ";
            if (CheckExcludeMask) sql += "NAME NOT LIKE '%" + mask1 + "%' AND ";
           

//---------------------------вот проблемная строка ------------------------------
           if (CheckCreation) 
               sql += "convert(datetime, CreationTime) between convert(datetime, '" + Cr_start + "') and convert(datetime, '" + Cr_End + "') ";
                            
  try
            {
                SqlCeCommand com = new SqlCeCommand(sql, con);
                SqlCeDataAdapter da = new SqlCeDataAdapter();
                da.SelectCommand = com;
                da.Fill(global.dtFsrez);
            }
            catch (Exception ex)
            {
                MessageBox.Show("GetFilesSrez\n" + ex.ToString()+"\nСодержимое запроса\n\n"+sql);
            }
        }

 string sql = "SELECT * FROM Files Where ";
            if (CheckIncludeMask) sql += "NAME LIKE '%" + mask1 + "%' AND ";
            if (CheckExcludeMask) sql += "NAME NOT LIKE '%" + mask1 + "%' AND ";
            if (CheckCreation) sql += " CreationTime between @date1 and @date2";
      
            SqlCeCommand com = new SqlCeCommand(sql, con);
            SqlCeDataAdapter da = new SqlCeDataAdapter();
            com.Parameters.Add("@date1", SqlDbType.DateTime, 8).Value = Cr_start;
            com.Parameters.Add("@date2", SqlDbType.DateTime, 8).Value = Cr_End;
            try
            {
                da.SelectCommand = com;
                da.Fill(global.dtFsrez);
            }