Responsive Designs

I've recently started teaching myself Javascript. I'd thought I'd see how object orientated prorgamming is handled in Javascript and as a result have written up this simple player creation and am just wondering whether I'm approaching this correctly? /** * Player Constructor */ function Player() { this.username; this.password; } /** * Player Username Setter * * @[member="param"] username * The Username to be set */ Player.prototype.setPlayerUsername = function(username) { // Check undefinied if(typeof username != 'undefined') { // Set Player Username this.username = username; } else { console.log("Please enter a valid parameter..."); } } /** * Player Password Setter * * @[member="param"] password * The Password to be set */ Player.prototype.setPlayerPassword = function(password) { // Check undefined if(typeof password != 'undefined') { // Set Player Password this.password = password; } else { console.log("Please entier a valid parameter...") } } /** * Player Username Getter * * @return The Current Player's Username */ Player.prototype.getPlayerUsername = function() { return this.username; } /** * Player Password Getter * * @return The Current Player's Password */ Player.prototype.getPlayerPassword = function() { return this.password; } /** * Create new Player * * @[member="param"] username * The Player's Username * @[member="param"] password * The Player's Password */ Player.prototype.create = function(username, password) { this.password = password; this.username = username; // new Player Object var player_to_create = new Player(); player_to_create.setPlayerUsername = username; player_to_create.setPlayerPassword = password; // log output console.log("Player Created: " + this.username + " " + this.password + "."); // save } Player.prototype.create(prompt("Enter a desired Username..."), prompt("Enter a desired Password...")); Thank you for any feedback.