.CommandType CommandTyis not getting updated with 5000 result

I am trying upload my Checkboxlist with 5000 recored at a runtime 

i used Sql query as datasource 

my sql query is returning more han 5000 rows 

but in my Checkboxlist only shows 100 records 

Can you lease tell me where i m wrong 

   .CommandType = CommandType.StoredProcedure
                .CommandText = "proc_Emp"
                .Connection = myconn2
                .Parameters.AddWithValue("@Emp", Emp)
                .Parameters.AddWithValue("@Emptype", Emptype)

                datareader = .ExecuteReader
            End With
            If datareader.HasRows = True Then
                TeacherCheckboxlist.DataSource = datareader
                EmpCheckboxlist.DataTextField = "Emp"
                EmpCheckboxlist.DataValueField = "Emp"
                EmpCheckboxlist.DataBind()
                datareader.Close()
                EmpCheckboxlist.Visible = True
            End If