#!/usr/local/bin/perl -w

@BankIN = (1,2,3);
@BankOUT = (4,4,4);
use strict 'subs';

arrayX(\@BankIN, \@BankOUT);

sub arrayX{

   my($a1, $a2)=@_;
   my $BankCount = 0;
   my $arg       = shift(@ARGV);

       print "$#a1\n";

       while ($BankCount <= $#a1 )

           {
               if ($a1[$BankCount] eq $arg)

               {
                  $arg = $a2[$BankCount];
                  $BankCount = $#a1;
               }
                $BankCount++;
            }

        print "$arg\n";
}