Database Software

hi,

my OS is Sun solaris,

DB version--10.2.0.2.0

i am trying to run a RCV file for offline backup through RMAN.
but when it never reaches to

alter database open;

the code is

connect target RMAN/*****@abcd

startup force dba;
shutdown immediate;
startup mount;

configure retention policy to recovery window of 31 days;
configure controlfile autobackup on;
configure default device type to sbt;
configure device type sbt parallelism 1;
configure channel device type sbt format '%d_%s_%t_%p';

RUN
{
set command id to 'RMAN off full to nsr';
backup database;
}    \\===============> full backup is successful here.

alter database open; //=================>but never reaches to this line

RUN
{
allocate channel d1 device type disk;
copy current controlfile to '/aib-oa/ar/oraA378/backup/copy_A378.ctl';
release channel d1;
}

allocate channel for maintenance device type disk;

RUN
{
delete noprompt backup of spfile completed before 'sysdate-7';
}

what's wrong with the script?

any help on this...

thanks