hash_walk($element);

sub hash_walk
{
  my $element = shift;
           
  if(ref($element) =~ /HASH/ )
  {    
      foreach my $key (keys %$element)
      {
          if ($key =~ /field/)
          { 
             # do something here? 
             print "found $$element{$key}\n";
          }   
          hash_walk($$element{$key});
      }
  }
  elsif (ref($element) =~ /ARRAY/)
  {
      foreach my $index (@$element)
      {
        hash_walk($index);
      }
  }  
}