Error: write after end

var Profile = require("./profile.js")


// Handle the HTTP route GET / and POST  / i.e. Home
    function home(request, response) {
        //if url = "/" && GET
            //url is a property of the incoming message
        if (request.url === "/") {
                //show search field
            response.writeHead(200, { 'Content-Type': 'text/plain' });
            response.write("Header\n");
            response.write("Search\n");
            response.end("Footer\n")
        }    

            //if url = "/" && POST
                //redirect to /:username
    }


// Handle the HTTP route GET / :username i.e. /mauricetafollacunningham
    function user(request, response) {
    //if url = "/....."
    var username = request.url.replace("/", "");

    if (username.length > 0) {
        response.writeHead(200, { 'Content-Type': 'text/plain' });
            response.write("Header\n");
            //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
                }
                //****!!!!!!LINE 43 IS RIGHT BELOW THIS COMMENT!!!!!!!!****
                response.write(values.username + " has "+ values.badges + " badges\n");
                response.end("Footer\n");
            });
            //on "error"
            studentProfile.on("error", function(error){
            // show error
                response.write(error.message + "\n");
                response.end("Footer\n")
            });

        }

    }

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