Help with arrays? complicated?

I need to create a program that will do two things-

1- load images from an array, 5 at a time, then based on interval, one at a time they are replaced by the next image in the array until it gets to then end, then repeat.

2- same idea, only needs to load 5 random images, then based on interval, one at a time they are replaced by the next random image in the array, without repeating a previously viewed image, until there are no more images, then repeat.

I have the code going great until I get to the part about replacing the images with different ones…

//write the picture array- Ai is the Array #
picture_array = new Array();
var Ai = 0;
while (Ai<59){
	trace("loop "+Ai);
	picture_array[Ai] = "pic_mc"+Ai;
	Ai += 1;
if (Ai == 59){
// get tweens
import mx.transitions.Tween;
import mx.transitions.easing.*;

// set the timing
var Timer;
Timer = setInterval( inOrder, 1000, "called");
// then populate stage with photos in order
var i = 0;
function inOrder(jfjf){
	duplicateMovieClip(oval_mc, "oval_mc"+i, i);
	trace("loop "+i);
	_root["oval_mc"+i].attachMovie(picture_array*, "tri_mc"+i, i);
	//_root["oval_mc"+i]._rotation = -i*60;
	_root["oval_mc"+i]._alpha = i*20;
	_root["oval_mc"+i]._xscale = 50;
	_root["oval_mc"+i]._yscale = 50;
	var pic_tween:Object = new Tween(_root["oval_mc"+i], "_y", Regular.easeOut, 450, -200, 10, true);
	pic_tween.onMotionFinished = function() {
	i -= 1;
	i += 1;
	if (i == 6){

Any tutorials or help you can point me to would be awesome. Thanks!