Phaser 2 worldBounds: How to enable left and right world collision and disable up and down

I’m making a platformer and I want the character to be able to drop out of the game like in Mario but I can’t find the correct function in Phaser2. I tried using but it only works to resize the game box. Somebody help me.

this.physics.arcade.checkCollision.up = false;

i’ll try it, thanks

| this.physics.arcade.checkCollision.up
really helpful, thanks : )