Checking if a zone is an instance

[Asylum]

Here is an instance generator/destroyer npc I use in gfaydark to generate level-appropriate instances of crushbone.

sub EVENT_SAY {
	my $EnterInst = quest::saylink("Enter the Instance", 2);
	my $Destroy = quest::saylink("destroy", 2);
    my $worse = quest::saylink("worse", 2);
	my $evil = quest::saylink("evil", 2);
	my $InstId = quest::GetInstanceID("crushbone", $version);

	if($text=~/hail/i){
		quest::say("Thank Tunare you're here, $name!  Something dreadful is taking place inside Crushbone.  Yes, yes, I realize that the whole place is dreadful to begin with.  But it's much [$worse] now.");
	}
	if($text=~/worse/i){
		quest::say("Some new evil has moved in and set up shop, destroying everything inside.  Where the Crushbone Orcs were destructive and chaotic, this new [$evil] is much more of a threat to all of Tunare's creatures.");
	}
	if($text=~/evil/i){
		quest::say("If you are willing to assist us, I will need to ensure your safe passage.  Just say when you are ready and I can open a portal enabling you to [$EnterInst].  Also, if you are done fighting, or wish to start over, I can [$Destroy] any old instances that may be lingering.");
	}
	if ($text =~/Enter the Instance/i) {
		my $j;
		for($j=2; $j<=4; $j++) {
			my $version = $j;
			my $InstId = quest::GetInstanceID("crushbone", $version);
			if ($InstId > 0) {
				quest::MovePCInstance(58, $InstId, 166, -586, 3.13);
			}
			elsif ((quest::GetInstanceID("crushbone", $ulevel + 1)) > 0) {
				quest::MovePCInstance(58, quest::GetInstanceID("crushbone", $ulevel + 1), 166, -586, 3.13);
			}
			elsif ((quest::GetInstanceID("crushbone", $ulevel - 1)) > 0) {
				quest::MovePCInstance(58, quest::GetInstanceID("crushbone", $ulevel - 1), 166, -586, 3.13);
			}
			elsif (($ulevel >= (($version * 10) - 9)) && ($ulevel <= ($version * 10))) {
				my $i_id = quest::CreateInstance("crushbone", $version, 21600);
				quest::AssignGroupToInstance($i_id);
				quest::AssignToInstance($i_id);
				quest::MovePCInstance(58, $i_id, 166, -586, 3.13);
			}
		}
	}
	if($text=~/destroy/i){
		my $i;
		for($i=0; $i<=6; $i++) {
			quest::DestroyInstance(quest::GetInstanceID("crushbone", $i));
		}
	}
	if ($text =~/Daria sent me/i) {
		my $InstId = quest::GetInstanceID("crushbone", $version);
		if ($InstId > 0) {
			quest::MovePCInstance(58, $InstId, 166, -586, 3.13);
		}
		elsif ($ulevel >= 50 && (plugin::check_hasitemoncursor($client, 4621))) {
			my $i_id = quest::CreateInstance("crushbone", 6, 21600);
			quest::AssignGroupToInstance($i_id);
			quest::AssignToInstance($i_id);
			quest::MovePCInstance(58, $i_id, 166, -586, 3.13);
		}
	}
}