How to initialize the mail box

How to initialize the mail box :
(1)disable mailbox
CANMDER=00000000000000000000b
(2)setting the data change request
CANMCR=0000000100000000b（bit8CDR=1）
(3)change the mailbox's indentifiers,controlling the words and data(only the outbox can change data).
(4)back to the nomal mode
CANMCR=00000000000000000000b
(5)start the mailbox (ME=1)
After the initialization of the CAN, you can sending the data information by correct confirguration.