ListBox Web Server Control And Stored Procedure

Hi, I've a  ListBox Web Server Control where I select a list of cities
now I would like to create a stored procedure with the selected values... please note that I use metods like these for execute my Stored procedure
 
public DataSet Getgfdfgh(SqlConnection connection, String IDAttivitaTipo, DateTime DataInizio, DateTime DataFine)
        {
            ConnectionState currState = connection.State;
            if (((connection.State & ConnectionState.Open) != ConnectionState.Open))
                connection.Open();

            try
            {
                SqlParameter[] parameters = new SqlParameter[3];
                parameters[0] = new SqlParameter("@IDAttivitaTipo", IDAttivitaTipo);
                parameters[1] = new SqlParameter("@DataInizio", DataInizio);
                parameters[2] = new SqlParameter("@DataFine", DataFine);
                SqlCommand cmd = CreateStoreProcedureCommand("Getfhdfh", connection, parameters);
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                DataSet ds = new DataSet();
                adapter.Fill(ds);
                return ds;
            }
            finally
            {
                if ((currState == ConnectionState.Closed))
                    connection.Close();
            }
        }
 
 
How Can I manage a list of values ??

Thanks for help me!!