Conditional statements

[Pint0_Xtreme]

Is anyone familiar with making conditional [story] statements? For example, how would I go about testing if a specific planet is blockaded by an Imperial fleet before I pull a trigger?

 

Also, is there a way to set the PLANET_FACTION reward parameter to Land only? That trigger seems to be way too powerful. It wipes any hostile fleet that happens to be orbiting the planet.