Trying to find much better way to assert Types in javascript rather than comparing types in string using typeof

gistfile1.js

function assertType(obj, type) {
    return obj.constructor.name === type.name
}

console.info(assertType("test", String)); //true
console.info(assertType(1, String)); //false
console.info(assertType(1, Number)); //true

function Book(){};
function Desk(){};
var book = new Book();
console.info(assertType(book, Book)); //true
console.info(assertType(book, Desk)); //false

console.info(assertType([], Array)); //true
console.info(assertType(function(){}, Function)); //true

var testObj=new Object();
console.info(assertType(testObj, Object)); //True

console.info(assertType({}, Object)); //True

Note that there's NO WAY to beat "typeof" in performance.
Check it here for yourself: http://jsperf.com/am-type-assertion#run

Geeks, here the updated gist with prototype: https://gist.github.com/afshinm/4733756

Thank you Afshin for the prototype version :)