I need a Skript from someone

[MathBuster09]

Hey, I've been trying at this for hours now, I keep getting errors. I want to make the player get teleported back if they are not holding a piece of paper named "&bCourse Key 1" after they walk on glass.

on step on glass:
	set {_key1} to paper named "&bCourse Key 1"
	[living entities] isn't holding
		teleport player to (307, 4, -184, world)

I get 1 error, I does not understand line 3, thanks to anyone who can help!

[iOussamato_]

try "if player is not holding {_key1}:"

[Xcard]

I haven't skripted in 6 months but try this:

 

on step on glass:
	if player is not holding paper named "&bCourse Key 1"
		teleport player to (307, 4, -184, world)