Add a table to Module Database

1. Site administration -> Development -> XMLDB editor
2. Find your module and click [Load]
3. Click [Edit]
4. Click [New table] and fill in the detail
5. Click [Back]
6. Click [View PHP code]
7. Select action: create table
8. Select table: select your table name
9. Click "View"
10. Copy the code to mod/your_mod/db/upgrade.php
11. Change XXXXXXXXXX to new version number (e.g. 2011022301)
12. Open mod/your_mod/version.php, change $module->version to the new version number
13. Notification 
14. Done