Why will terminal not output postBody?

var Profile = require("./profile.js");
var renderer = require('./renderer');
var querystring = require('querystring');
var commonHeaders = {'Content-Type': 'text/html'};

//Handle HTTP route GET / and POST / i.e. Home
function home(request, response) {
  //if url == "/" && GET
  if(request.url == "/") {
    if(request.method.toLowerCase() === "get") {
      //show search
      response.writeHead(200, commonHeaders);
      renderer.view("header", {}, response);
      renderer.view("search", {}, response);
      renderer.view("footer", {}, response);
      response.end();
    }
    //if url == "/" && POST
  } else if (request.method.toLowerCase() === "post"){
    //get POST data from body
    request.on("data", function(postBody) {
      //extract username
      var query = querystring.parse(postBody.toString());
      response.write(query.username);
      response.end();
      //redirect to /:username
    });


  }
}

//Handle HTTP route GET /:username i.e. /chalkers
function user(request, response) {
  //if url == "/...."
  var username = request.url.replace("/", "");
  if(username.length > 0) {
    response.writeHead(200, commonHeaders);
    renderer.view("header", {}, response);

    //get json from Treehouse
    var studentProfile = new Profile(username);
    //on "end"
    studentProfile.on("end", function(profileJSON){
      //show profile

      //Store the values which we need
      var values = {
        avatarUrl: profileJSON.gravatar_url,
        username: profileJSON.profile_name,
        badges: profileJSON.badges.length,
        javascriptPoints: profileJSON.points.JavaScript
      }
      //Simple response
      renderer.view("profile", values, response);
      renderer.view("footer", {}, response);
      response.end();
    });

    //on "error"
    studentProfile.on("error", function(error){
      //show error
      renderer.view("error", {errorMessage: error.message}, response);
      renderer.view("search", {}, response);
      renderer.view("footer", {}, response);
      response.end();

    });

  }
}

module.exports.home = home;
module.exports.user = user;