Plese answer some FAQs

Hello Dear friends..!!!!!!!!!

I have some Query's please answer the following:

1. what is the prerequisite of select single *....?

2. what is the difference b/w cluster tables and transparent tables..

3. Give some example of Cluster tables..?

4. why r u creating main windows in SAP SCRIPTS why only one main window y not more..?

Thanks

Regards

BABU