how to upload an image as multipartform data in node.js

The answer of this question is as follow :

fileupload.js :

var express = require("express"),                                                                
    app = express();                                                                             

// tell express to use the bodyParser middleware                                                 
// and set upload directory                                                                      
app.use(express.bodyParser({ keepExtensions: true, uploadDir: "uploads" }));                     
app.engine('jade', require('jade').__express);                                                   

app.post("/upload", function (request, response) {                                               
    // request.files will contain the uploaded file(s),                                          
    // keyed by the input name (in this case, "file")                                            

    // show the uploaded file name                                                               
    console.log("file name", request.files.file.name);                                           
    console.log("file path", request.files.file.path);                                           

    response.end("upload complete");                                                             
});                                                                                              

// render file upload form                                                                       
app.get("/", function (request, response) {                                                      
    response.render("upload_form.jade");                                                         
});                                                                                              

app.listen(3000);

View :

doctype 5
html
    head
        title Upload Form
    body
        h1 Upload File
        form(method="POST", action="/upload", enctype="multipart/form-data")
            input(type="file", name="file")
            input(type="submit")