I think this is better

#!/usr/bin/perl --

use strict;
use warnings;

use XML::Twig;
use Digest;


            
my $xml = q~<Transaction>
    <MessageCode>100</MessageCode>
    <ToAccountNo>12989898900</ToAccountNo>
    <ToBranchCode>08876</ToBranchCode>
    <FromAccountNo>S MARR SON </FromAccountNo>
    <FromBranchCode>ABG89097</FromBranchCode>
    <CurrencyCode>INR</CurrencyCode>
    <Amount>0000000000221000000.00</Amount>
    <TransactionDate>2008-07-10T12:04:25</TransactionDate>
    <ValueDate>2008-07-10</ValueDate>
    <CustomerRefNo>/CUST/</CustomerRefNo>
    <ReferenceNo1>ADH7870822</ReferenceNo1>
    <ReferenceNo2>/FRASER TRANSACTION</ReferenceNo2>
    <DealerCode>1780</DealerCode>
    <SalesOrganisation>1000</SalesOrganisation>
    <TransactionType>N</TransactionType>
    <SequenceNo>1</SequenceNo>
  </Transaction>~;


{
    my $ctx = Digest->new('SHA1');# MD5 ...
    my $t = new XML::Twig(
        TwigHandlers=> {
            Transaction => sub {
                print $_->children_text,$/;
                $ctx->add($_->children_text);
            }
        }
    );


    $t->parse($xml);

    print $/, $ctx->hexdigest,$/;

    undef $ctx;
    undef $t;
}

__END__
1001298989890008876S MARR SON ABG89097INR0000000000221000000.002008-07
+-10T12:04:252008-07-10/CUST/ADH7870822/FRASER TRANSACTION17801000N1

e5dc8115e0a2c22ffd034e07d4db8446b9d6696e
# FInal data will be as below
1001298989890008876S MARR SON ABG89097INR0000000000221000000.002008-07
+-10T12:04:252008-07-10/CUST/ADH7870822/FRASER TRANSACTION17801000N1
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