checkedlistbox with database

Question

Hello
please can you help me
I have 3 tables
I- Users (id,U_name,pass)
II- Privileges (Pri_num,Pri_Type)
III- Users_Privileges (id,Pri_num)
and i have checkedlistbox used to show the items of Table II ( Pri_Type) and the value of these items also from Table II (Pri_num) and the idea now that when i add a new user and the checked for one or more of the checkedlistbox data is stored in Table III by (id) for this user with The value of the checkedlistbox (Pri_num)
how to do it ,please help me to do it in my programs
note:
i used c# 2008 and sql server 2005 enterprise
thank you for your cooperation