Trigger events?

hey guys so im creating a lens, when a object falls from top screen towards down, but when i open my mouth, the object should dissapear.

Now i am being able to do that atm but it works as a toggle

this is the script i use for turning on and off of a target object tht hits falling object

// @input SceneObject[] obj

var event = script.createEvent("MouthOpenedEvent");

event.faceIndex = 0;

event.bind(function (eventData)

{

if(!script.obj[0].enabled){

script.obj[0].enabled = true;

} else {

script.obj[0].enabled =false;

}

});

please tell me solution for this ASAP!