Script/JS syntax to check if a skill is instant cast? (Yanfly.22)

Hi,
I'm wondering if there's any way to determine thru javascript if a skill the actor is using is instant cast or not (Using Yanfly's Instant Cast Plugin)?
something like
if (this.isInstantSkill)
so that code only runs if the skill is instant

Not sure if it will work but try this:
You need to specify which actor it is and the item/skill you are checking for.

How does one reference an item?
I'm currently using
var user = actor.currentAction();
var skill = action.item();
but action and skill are both undefined when i print to console.

code is
<Custom Action Start Effect>
var Q1 = 74;
var Q2 = 75;
var Q3 = 76;
var Q4 = 77;

// Check if the action exists, is a skill
if (action && action.isSkill()) {
var action = user.currentAction();
var skill = action.item();
if(user.isInstantCast(skill)){
if (user.isStateAffected(Q4)){
user.removeState(Q4);
user.addState(Q3);
}
else if (user.isStateAffected(Q3)){
user.removeState(Q3);
user.addState(Q2);
}
else if (user.isStateAffected(Q2)){
user.removeState(Q2);
user.addState(Q1);
}
}
}
console.log(user.isInstantCast(skill));
console.log(user.currentAction());
console.log(action);
</Custom Action Start Effect>