Help! Cannot remove movie clip from array

programming flash
1

I am trying to remove a movie clip from an array (i am not an expert programmer so please bare with me:)

I create my array in my main timeline, then within a movie, when a user clicks a button, that movie clip should be deleted from the array in the main timeline and new random clip play in its place. Its all working except for the delete movie clip from the array part so movie clips are replaying when they should be deleted. Here is the code for my button. Any help would be greatly appreciated as I have spent hours messing with this:

//button when user clicks right answer
function easyRight8(pEvent:MouseEvent):void {

//increase players score
MovieClip(root).playerScore++;
MovieClip(root).updateTextFields();

//play random clip from array when this button pressed
var myNumber = Math.floor(Math.random()*MovieClip(root).storeArray1.length);
trace("myNumber "+myNumber);
var activeCarton = MovieClip(root).storeArray1[myNumber];
activeCarton.visible = true;
activeCarton.gotoAndPlay(2);

//make this movie clip not invisible on main timeline
this.visible = false;

//remove this movie clip from array so it no longer plays
MovieClip(root).storeArray1.splice(this,1);
trace (MovieClip(root).storeArray1);

}