Parse tags into arrays

Hello,

I am writing a PERL code. The code is given a file which has data in the format of :

<Tag Name> <Tag value>

e.g. :

FIRSTNAME DAVID

Now, the file to be processed by the PERL code has data something like this :

TAGSTART
FIRSTNAME DAVID
LASTNAME RHODES
<some other tags>
<some other tags>
ACCOUNT 1000901
<some other tags>
<some other tags>
BILLAMOUNT 4200
<some other tags>
<some other tags>
TAGEND

The entire set of tags from TAGSTART through TAGEND are repeated multiple times in a file. The number of times of repetition is not fixed in a file.

The PERL code is required to process the file such that we have 1 array of the following pairs :

"ACCOUNT" tag value - "BILLAMOUNT" tag value

Could please point out any approach that would be the best to achieve this ?

Thanks.