Missing Hook - Ignoring Conditions Except When They Apply

I want a click ignored if a hook isn't present:

(click: ?Bunyon)[(if: $located is "Quicksand")[(goto: "Lakeside")]

This works when the hook is present, but when it isn't says -

The (click:) command should be assigned to a variable or attached to a hook.

So, I want to do something to test if the hook is present - like this:

(if: $inv contains "Rusty Axe")[(click: ? ... etc.]

Or maybe -

(if: $inv contains "Rusty Axe" and click: ? ... etc.]

But that doesn't work either.

Any help would be gratefully appreciated.