[Bioperl-l] EMBL format field

[Wen Huang]

Hi all,

I have a EMBL file that I want to extract one of the line

###file###
ID   BAA19060; SV 1; linear; mRNA; STD; MAM; 2115 BP.
XX
PA   AB000170.1
XX
DE   Sus scrofa (pig) endopeptidase 24.16 type M1
XX
OS   Sus scrofa (pig)
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;  
Mammalia;
OC   Eutheria; Laurasiatheria; Cetartiodactyla; Suina; Suidae; Sus.
OX   NCBI_TaxID=9823;
.........

I want the accession number in the line that starts with PA, AB000170  
in this example.

Can anybody kindly help, tell me which module and method I should use?  
I tried various things like $seq_obj -> primary_id, display_id,  
get_secondary_id, etc.. they did not work...

Thanks a lot!

Wen