Grab all names of your friends in a list and create an array out of them to use for further functions. Open up the list and click "Manage List" > "Edit List". Then run this script in the browser console.

fb_list_friends_names.js

var items = [],
    textItems = [];
items.push(document.querySelectorAll(".friendListItem"));
for (var i = 0; i < items[0].length; i++) {
    textItems.push(items[0][i].childNodes[2].textContent);
};
textItems;