If this is exactly the code you're dealing with, then some of the if's can be removed:

• if($action) {
      #Bond the built-in and accessory components to the parent.
      if($action eq "BOND") {
  [download]

  You don't need the first if.

• for my $acc (@acc) {
  ...
  if ($current_status->{"curr_parent_id"} != 0) {
      print "Refusing to modify the status of demstock $acc. It has alre
  +ady been moved<br>\n";
  } else {
      ...
  }
  [download]

  can be flattened out to

  for my $acc (@acc) {
  ...
  if ($current_status->{"curr_parent_id"} != 0) {
      print "Refusing to modify the status of demstock $acc. It has alre
  +ady been moved<br>\n";
      next;
  }
  ...
  [download]

  which removes one level of indentation (and again in the second loop).

The other three levels are necessary, since you're testing three different conditions: the value of $action, the location, and the elements of @built (well, unless you're willing to start calling DIE to abort the flow).

I'd suggest that you use separate variables for the queries though, rather than recycling $sth all the time. Then (as well as being more readable), they can be pre-prepared, using placeholders.

--
Tommy
Too stupid to live.
Too stubborn to die.