I don't know what I was thinking. The correct way is to say $_[0] instead of just $_ (i.e., $_[0]->{hash_key})

My mistake. Thanks for the help.

Try doing Dumper(@_) before you do anything else in your routine

Sorry about any confusion, but the rather cryptic (because of line breaks, what not) block of text in the code tags (with $VAR1) is the text resulting from a print Dumper @_statement.