Clearing db_Tables and Userdefined tables

Hi,

I created Userdefined Tables like Documents and Document Rows.

In this, while Testing Docentry,Docnum values are increasing up to 500.

how to bring this values from 500 to 1 .

and also i want to Restore this database in some other system

How to clear all db_tables and Userdefined Tables in SapBusiness One.

Regards,

Nagabau.