How do I make a sprite fall over while being attacked.

I'm making a zombie game and I'm curious as to when I make my zombie sprite attack my victim sprite, the victim falls onto his back.

-Killer Jay17

if victim on collsion with zombie & zombie.x-victim.x>0 then

victim.x +30

if victim on collsion with zombie & zombie.x-victim.x<0 then

victim.x -30