Searching For Multiple Words Within A String Or Array?

How would one search for more than one one simultaneously? I have this function:

var flix = ["Any items left unattended on this table" , "Hello, World"];

function Multiwords(s){
var a = flix[0].toLowerCase();
var b = s.toLowerCase();
var result = a.indexOf(b)
if (result >= 0)

[Code]...

It's pretty basic, it just searches through the first index of var flix and tells me if the parameter (s) is 'found' or 'not found'. I made it not to be case sensitive. However, how would I search for multiple words for example:

Multiwords("ANY items This") and if any combination of 'ANY' or 'items' or 'This' is found, i still get my alert message of 'Found'?