Node.js parameters not passed correctly to router

Im new to node.js. I have server.js , router.js, index.js and requestHandler.js files in my project. i pass start or upload in url like below

http://localhost:8888/start

I get pathName from url and pass it to router.js in server like below:

server.js :

var http = require("http");
var url = require("url");
function start(route,handle){
function onRequest(request, response) {
    var pathname = url.parse(request.url).pathname;
    console.log("Request for " + pathname + " received.");
    route(handle,pathname);
    response.writeHead(200, {"Content-Type": "text/plain"});
    response.write("Hello World");
    response.end();
}
http.createServer(onRequest).listen(8888);
console.log("Server has started.");
}
exports.start = start;

router.js :

function route(handle,pathname){
console.log("About to route a request for "+ pathname );
if(typeof handle[pathname]==='function'){
    handle[pathname]();
}else{
    console.log("No request handler found for "+pathname);
}
}
exports.route = route ; 

index.js :

var server = require("./Server");
var router = require("./router");
var requestHandlers = require("./requestHandler");

var handle={}
handle["/"]=requestHandlers.start;
handle["/start"]=requestHandlers.start;
handle["/upload"]=requestHandlers.upload;

server.start(router.route,handle);

requestHandler.js :

function start(){
console.log("Request handler 'start' was called.");
}

function upload(){
console.log("Request handler 'upload' was called.");
}

exports.start=start;
exports.upload=upload;

I get wrong result :

PS C:\Program Files\nodejs> node ..\..\Users\private\Desktop\hello\index.js
Server has started.
Request for /start received.
About to route a request for /start
No request handler found for undefined
Request for /favicon.ico received.
About to route a request for /favicon.ico
No request handler found for undefined
Request for /favicon.ico received.
About to route a request for /favicon.ico
No request handler found for undefined

instead of this :

Server has started.
Request for /start received.
About to route a request for /start
Request handler 'start' was called.

what is the problem? any idea?