Random select array item without duplicates without removing items (JavaScript)

I have seen many questions concerning randomly selecting array items without repeating. However, most of them are answered by using the splice method. But this removes items.

I have already selected my items randomly, but they are repeating. In my two functions I select from each randomly selected item two "sub-items". The two functions are not working together, I am looking for a way that it is possible to select two different randomly selected items, without repetition, and without removing them. Can one please help me out?

(Using Adobe Edge Animate)

var xml_source = "series.xml";
var initLoadScript = false;

var items = [];
var itemTitle1;
var obj = new Object();
var previousNumber = -1;

loadXML();

function loadXML() {
        $.ajax({
                type: "GET",
                url: xml_source,
                dataType: "xml",
                success: function(xml) {

                        $(xml).find('sbs').find('channel').find('item').each(function() {
                                items.push($(this));
                        });

                        itemOne();
                        itemTwo();
                }
        });
}

function itemOne(){
        var randomNumber = Math.floor(Math.random()*14);
        var assignItem = randomNumber;
        console.log("random nummer 1: " + assignItem);
        sym.$("TitleText1").html(items[assignItem].find("author_name").text());
        sym.$("Image1").html("<img src='"+items[assignItem].find('media\\:content, content').find('media\\:thumbnail, thumbnail').attr('url')+"' width='145'/>");
}

function itemTwo(){
        var randomNumber = Math.floor(Math.random()*14);
        var assignItem = randomNumber;
        console.log("random nummer 2: " + assignItem);
        sym.$("TitleText2").html(items[assignItem].find("author_name").text());
        sym.$("Image2").html("<img src='"+items[assignItem].find('media\\:content, content').find('media\\:thumbnail, thumbnail').attr('url')+"' width='145'/>"); 
}