Destroy object on button push?

I want my player to destroy a cube when the down arrow key is pressed on a keyboard. I know I need to use the Destroy (Object); command but what would be the entire script?

class destroyObjectScript {

   void Update() {
     if(Input.GetKeyDown(valueForArrowDownKey) {
       Destroy(gameObject);
     }
   }

}

I would tell you to look up what the value for the Arrow down key is, but since it appears to be down, the IDE will probably help you auto-complete it.

thats what i get for copying the above text

class destroyObjectScript {

void Update() {

 if(Input.GetKeyDown(KeyCode.DownArrow)) {
   Destroy(gameObject);
 }

}

}