Deep Object Merge in js

gistfile1.js

function merge(target, obj) {
    var ret = {};
    for (var prop in obj) {
        if (target.hasOwnProperty(prop) && obj.hasOwnProperty(prop)) {
            if (typeof(target[prop]) === "object" && typeof(obj[prop]) === "object") {
                ret[prop] = merge(target[prop], obj[prop]);
            } else {
                ret[prop] = obj[prop];
            }
        } else if (obj.hasOwnProperty(prop)) {
            ret[prop] = obj[prop];
        }
    }
    for (var prop in target) {
        if (!(prop in obj) && target.hasOwnProperty(prop)) {
            ret[prop] = target[prop];
        }
    }
    return ret;
}