my address book stoped working. i dont know what happen but all address are gone and i cant add any new one's. How can i reload the address book or do i have to get another address book to install???

Wirelessly posted (8700g: BlackBerry8700/4.2.1 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/100)

First of all, try a hard reset.

http://blackberryfaq.com/index.php/1st_step_to_take_if_device_is_having_problems%3F

Wirelessly posted (BlackBerry 8700g: BlackBerry8700/4.2.1 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/100)

If that doesn't work, had you ever synched the BlackBerry with your computer? i.e. With Outlook or another PIM software? If so, trying synching againg to bring the contacts back to the BlackBerry after a hard reset. Or if you have a backup try restoring the address book database.