"20 minute" string search challenge

string_search.js

// lol global
var index = {};

function add(content, uid) {
    contentArray = content.split(" ");
    index[uid] = {};
    for (i = 0, len = contentArray.length; i<len; i++) {
	index[uid][contentArray[i]] = true;
    }
}

function search(query) {
    var result = [];
    queryArray = query.trim().split(" ");
    for (var key in index) {
	if (containsAll(queryArray, index[key])) {
	    result.push(key);
	}
    }
    return result;
}

function containsAll(splitQuery, page) {
    for (j = 0, len = splitQuery.length; j<len; j++) {
	if (!contains(splitQuery[j], page)) {
	    return false;
	}
    }
    return true;
}

function contains(word, page) {
    return (!!page[word])
}

// TESTS

add("puppies kittens", 9);
add("kittens", 10);
add("puppies", 8);
add("dog cat", 6);

console.log("printing index");
console.log(index);

console.log("just puppies:")
console.log(search(" puppies"));
console.log("just kittens");
console.log(search("kittens "));
console.log("puppies and kittens:");
console.log(search("puppies kittens"));
console.log(search("hot dog"));
console.log(search("cat dog"));
console.log(search("puppies"));

console.log("OLD TESTS better return true or we're really in trouble :c");
console.log(contains("dog",{dog: true}));
console.log(contains("dog",{hello: true, is: true, dog: true}));
console.log(containsAll(["my","milkshake"],{my: true, milkshake: true, brings: true, all: true}));
console.log(containsAll(["milkshake"],{milkshake: "milkshake"}));

I removed the contains function, added var to the for loop variables, and renamed a few variables. But looks great!
https://gist.github.com/paulvstheworld/9560591

I don't know javascript very well, but the code looks pretty readable.

// lol global
var index = {};
(at first I thought index was a special js keyword, haha)