npc 2 states animation

Hi guys i have a guy with an idle animation that i would like to play until the players state changes . i would like 2 states (idle)(trading) the guy is stood next to a cart and i would like to eventually trade with him .

i dont have a trading animation yet but i would like to set a variable called trading .and have the npc be in idle whilst (trading) is false …

there appears to be hundreds of unreal tutorials pertaining to npcs attacking walking around etc …but i simply want to play an idle animation until the value of trading is true

any help guys?