Skript na działki

Napisałem taki skrypt i zastanawiam się jak dodać do tego kodu zabezpieczenie żeby inny gracz nie mógł zakładać działki na terenie na którym już jest założona działka przez innego gracza
 

command /dzialka [<text>]:
	trigger:
		if arg 1 is "zaloz":
			if distance between {ustawiony.spawn} and location of player is greater than 1:
				if {posiadanie.dzialki.%player%} is not set:
					set {posiadanie.dzialki.%player%} to true
					set {dom.dzialka.%player%} to location of player
					set {srodek.dzialka.%name of player%} to location of player
					add {srodek.dzialka.%player%} to {jakas.dzialka}
					op the player
					Execute player command "//pos1" 
					Execute player command "//pos2"
					Execute player command "//expand 20 n"
					Execute player command "//expand 20 s"
					Execute player command "//expand 20 e"
					Execute player command "//expand 20 w"
					Execute player command "//walls 101"
					Execute player command "//expand vert"
					Execute player command "/rg define dzialka%player%"
					Execute player command "/rg addowner dzialka%player% %player%"
					deop the player
				else:
					send "&4Posiadasz juz dzialke"
			else:
				send "&4za blisko spawn"
		if arg 1 is "usun":
			if {posiadanie.dzialki.%player%} is set:
				clear {posiadanie.dzialki.%player%}
				clear {srodek.dzialka.%player%}
				op the player
				Execute player command "/rg remove dzialka%player%" 
				deop the player
			else: 
				send "&4nie posiadasz dzialki"
		if arg 1 is "dodaj":
		if arg 1 is "wyrzuc":
		if arg 1 is "dom":
		if arg 1 is "ustawdom":
		if arg 1 is "ustawspawn":
			if player have permissions "dzialki.admin":
				set {ustawiony.spawn} to location of player
				send "&4ustawiono spawn dzialki"