get authenticating user's name for further usage

get authenticating user's name

// test to get logged in user's name for further use   
  $.getJSON("http://tlinkstimeline.appspot.com/loggedinuser?callback=?", function(loggedinuser){
    if (loggedinuser) {
        var thename = loggedinuser;
        console.log("hello " + thename);
        };
      });