on rightclick on iron bars:
    if player is holding an iron nugget:
        if player's gamemode is survival:
            set {ciernie.%targeted block%} to true
            remove an iron nugget from player's inventory
        else:
            set {ciernie.%targeted block%} to true
        send "&7Dodano cierń do kraty żelaznej."
        
on walk on iron bars:
    while block under player is iron bar:
        if {ciernie.%block under player%} is true:
            damage player by 0.5 heart
            wait 3 ticks
            
on break of iron bar:
    if {ciernie.%event-block%} is set:
        delete {ciernie.%event-block%}