How do I make the player change it's z order depending on where it is?

I'm currently working on a survival game where you have to collect a certain amount of "Giftys" in order to win the game. I want to make it so the player moves behind the Gifty when they're below it, and in front when they're above it. I want the player to do this for each individual Gifty but s far everything I've tried doesn't work. I was wondering whether anyone would know how to fix this?

Here's my current events in case you need them:

Thanks!

Moved to the How Do I...? Forum

Instead of Y, you can compare the sprite.BBoxBottom

OR

In case of sprites with empty space in them... it is better to add a new image point for the bottom, then compare using

sprite.imagepointY("img point name")

Check out this demo

howtoconstructdemos.com/z-sorting-in-an-isometric-view-game