Random alphanumeric string generation

gistfile1.js

function randomChunk() {
    return (Math.random() * Number.MAX_VALUE).toString(36);
}

function randomString(length) {
    var result = '';

    do {
        var chunk = randomChunk();
        var overhead = result.length + chunk.length - length;
        if (overhead > 0) {
            result += chunk.slice(0, chunk.length - overhead);
        } else {
            result += chunk;
        }
    } while (overhead < 0);

    return result;
}