[Trigger] No attack on a specific unit

[Null]

How do I make a specific unit stop auto-attacking a unit type?
Pls show me the trigger.

 

[Warseeker]

• Prevent Attack
  • Events
    • Unit - A unit Is attacked
  • Conditions
    • (Unit-type of (Attacking unit)) Equal to Footman
    • (Unit-type of (Attacked unit)) Equal to Rifleman
  • Actions
    • Unit - Order (Attacking unit) to Stop

 

[Null]

Thanks!