Error in implement .Net Remoting project

See more:

C#

.NET

remoting

Hi all,
I'm implementing .Net Remoting Project but it occurs some problem, pls help me.
I code proxy object to comunicate between client and server as:

public class clsComponent : MarshalByRefObject
    {
        public DataSet TransDetails(string strServer)
        {
            string strConnectString = "server = " + strServer + "; database = ImperialBank; UID=phuc;PWD=phuc";
            SqlConnection sqlCon;
            SqlDataAdapter sqlDataApt;
            string strQuery = "Select Transaction_Id as 'Transaction Id', Transaction_Date as 'Transaction Date', " +
                               "Credit, Debit, Bal_Amt as 'Balance Amount' from Transactions";
            sqlCon = new SqlConnection(strConnectString);
            sqlDataApt = new SqlDataAdapter(strQuery, sqlCon);
            DataSet ds = new DataSet();
            sqlDataApt.Fill(ds, "Transactions");
            return ds;
        }
        public IQueryable<CustomerDetail> fnGetAllEmp()
        {
            var c = from c1 in db.CustomerDetails
                    select c1;
            return c;
        }
}

Client was connected to server and client call TransDetails() => ok. But client call fnGetAllEmp(), it occur error:

Type 'System.Data.Linq.DataQuery`1[[ComponentApp.CustomerDetail, ComponentApp, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]' in Assembly 'System.Data.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.

Sorry my language!