bsearch.js

function bsearch(list, value) {
    var index1, index2;

    if (list.length === 1) {
        return list[0];
    } else if (list.length === 0) {
        return null;
    }

    index1 = 0;
    index2 = Math.floor(list.length / 2);
    if (list[index2] === value) {
        return list[index2]
    } else if (list[index2] < value) {
        return bsearch(list.slice(index2), value);
    } else {
        return bsearch(list.slice(index1, index2), value);
    }
}