Javascript Object deepExtend

deepExtend.js

Object.deepExtend = function(destination, source) {
    for (var property in source) {
        if (source[property] && source[property].constructor && source[property].constructor === Object) {
            destination[property] = destination[property] || {};
            arguments.callee(destination[property], source[property]);
        } else {
            destination[property] = source[property];
        }
    }
    return destination;
};

var dstObj = Object.deepExtend({name:'jason'}, {age:18});