How do I make knockback?

How to do that when you touch the opponent he bounces?

Perhaps by getting his X position and add or subtract (depending on which side he is in relation to the player) a value to it?

---> Player on collision with Enemy (this condition is a trigger, that's important)

-------->(sub-event 1) if Player.X < Enemy.X ---> Set Enemy X position to self.X + 30 (the enemy will be pushed 30 pixels to the right)

-------->(sub-event 2) if Player.X > Enemy.X ---> Set Enemy X position to self.X - 30 (the enemy will be pushed 30 pixels to the left)

I did some sort of knock-back for my ChocolateHearts game. what I did is I moved the enemy or the player a few pixels back based on where the hit came from. (player shoots the zombie - zombie gets hit by "blast" and is knocked back a few pixels )

Here's a screenshot of what I used in my events:

Thanks