create new company in dynamic nav

Please guys How i create new company in dynamic nav 2009 and what is the meaning of text box company type

and

if i have two companies for one database and i changed one of this company data are this change in database

click on file - company- new for new company

if you have changed data in new company then that data will changed in those company table and of course in database as same database hold that company tables

if i have two companies and i delete some data or objects from one company this will effect to another company

If you delete objects in one company then it will effect another company…

If you have DataPerCompany property of the table is No and if you delete data in one company then it will effect in another company also…

If DataPerCompany property is Yes, then it wont effect another company data…