Javascrip | I don't have any Idea to fix this Code (function statement requires a name)

I'm working on a Website who display Tweets. I try to make a if-clause with 2 funktions. 1. The var "twittername" disappears to the right side, change the Text from a xml file (this works already) and goes back the position. 2. The Twitterlogo make the same

My Problem is that Firefox give me a Error with "function statement requires a name".

if ($('#twittername').html() != twittername) {
                animating = true;
                $('#twittername').tween({
                    left: {
                      start: 1400,
                      stop: 5000,
                      time: 0,
                      duration: 2.5,
                      effect: 'easeIn'
                    }}),
                $('#twitterlogo').tween({
                    left: {
                      start: 1400,
                      stop: 5000,
                      time: 0.4,
                      duration: 2.5,
                      effect: 'easeIn'
                    }})
                    onStop: ;function(){
                        $('#twittername').html(twittername);
                    }
                };

                $('#twittername').tween({
                    left: {
                      start: 5000,
                      stop: 1400,
                      time: 3.5,
                      duration: 2.5,
                      effect: 'easeOut'
                    }
                    $('#twitterlogo').tween({
                    left: {
                      start: 5000,
                      stop: 1400,
                      time: 3.9,
                      duration: 2.5,
                      effect: 'easeOut'
                    },
                    onStop: function(){
                        animating = false;
                    }
                });
            }

I hope you can help