not allowing block placement if block doesn't have a certain name

[RunaYoutube]

im trying to make a skript where if you don't have a block with a certain name it wont let you place it but I cant figure out how to do it

on place of coal block:
    if name of player's held item = "&8&lCoal Gen"
    set {gens::%location of event-block%} to uuid of player
    if {gens::%player's uuid%} < 15:
        add 1 to {gens::%player's uuid%}
        while event-block is coal block:
            wait 60 ticks
            drop 1 coal above location of event-block
    else:
        cancel event
    else:
        send "" to player
        send "&bYou have reached your Gen Cap! &7%{gens::%player's uuid%}%&b/&715" to player
        send "" to player
        cancel event

 

[DeadlySkyLord]

every 3 seconds in "world":
    loop all indices of {gens::coal::*}:
        if block at loop-value is coal block:
            drop 1 coal above loop-value
        else if block at loop-value is not coal block:
            delete {gens::coal::%loop-value%}

on place of coal block:
    if name of player's held item = "&8&lCoal Gen":
        if {gens-used::%player's uuid%} < 15:
            add 1 to {gens-used::%player's uuid%}
            set {gens::coal::%location of event-block%} to uuid of player
            stop
        else:
            send "" to player
            send "&bYou have reached your Gen Cap! &7%{gens::%player's uuid%}%&b/&715" to player
            send "" to player
            cancel event
    else:
        cancel event