Enemy attacks player but only once

So I have an enemy that chases the player and attacks it once it interacts with the player's collider, but the enemy only attacks it a single time. I want it to attack the player multiple times until the player dies. I was thinking I should have the collision detection on the update method, but I'm not sure how to do it. Please, any help is appreciated. I've attached a PNG file of my script:![alt text][1] [1]: /storage/temp/182750-help-ref.png