Hi, DarioCrivelli, thanks again for your kind replied.

If events A and C are selected, your second page should subscribe to suitable items, like "eventAdetails" and "eventCdetails", that your Data Adapter has to supply. The table is able to show rows from both items...
What you are talking is the exactly scenario that I want. Just the thing that I don't understand is "subscribes to suitable items", what does it mean and how to do that?
and the statement "...your Data Adapter has to supply...", does it means that I have to add something extra in the adapters.xml other than just with the simple metadata and adapter_class? Following is the content in my adapters.xml:

<?xml version="1.0" ?>
- <adapters_conf id="RBMS_Demo">
- <metadata_provider>
<adapter_class>com.lightstreamer.adapters.metadata .LiteralBasedProvider</adapter_class>
</metadata_provider>
- <data_provider>
<adapter_class>com.lightstreamer.adapters.remote.d ata.NetworkedDataProvider</adapter_class>
<param name="request_reply_port">1001</param>
<param name="notify_port">1002</param>
</data_provider>
</adapters_conf>


Sorry for such many questions, because I couldn't understand it well by just referring to the documentation. Thanks.