NPC AI scripting

I have NPC's (non player characters) within a SP I am finishing and have a question about the AI (if it exists) scripting.

I need an NPC to either run left OR right at the end of a corridor depending on an outcome/Event I created.

I have tried the Action_IFCONDITION script,tried including Action_ENDSECTION,but the NPC either stops or runs one way(regarding that outcome/Event).

Is it that when they're scripted they only follow commands,zero to whatever..or can a scripted NPC be able to follow one Event,ignore the next,if asked to,and follow the other after?
I do understand the action_GOTOACTION procedure but cannot work out how to 'AI' it to 'think'.

I do hope someone could help.

Sure Angel_Mapper and thanks,I had thought of 'juggling' 2 pathnodes,either side,with the outcome triggering one to the floor and one up and away.

I suppose I'll have to use that option.

Heh,I have attachtag'd a pathnode or hidden weapon placement to move left and right before and the NPC has stood there and watched it move...that's good for 'intro' movie stuff.