moving from 7.4.13 to 8.0.14

Hi,

Currently I am using postgres 7.4.13 and I will like upgrade it to 8.0.14
I have backup my databases by using pg_dumpall (7.4.13)
pg_dumpall -U postgres > /root/backup_all_db

Is it doable to load the backup file using the psql (8.0.14) ?

Another question: Is it possible to upgrade 7.4.13 straight to 8.2?




Many Thanks,
Antonis