function retweet() {
 var bitly_id  = 'mjtv';
 var bitly_key = 'R_dc5b0574211ccf2b84c5c226ff96f1e0';

 api = 'http://api.bit.ly/shorten'
 + '?version=2.0.1'
 + '&format=json'
 + '&callback=retweetCallback'
 + '&login=' + bitly_id
 + '&apiKey=' + bitly_key
 + '&longUrl=';

 var script = document.createElement('script');
 script.type = 'text/javascript';
 script.src = api + encodeURIComponent(location.href);
 document.body.appendChild(script);
}
function retweetCallback(json) {
 var tid = 'MusicJapanTV';
 var d = document;
 var w = window;
 var l = location;
 var e = encodeURIComponent;
 var sel = '';
 if ( d.selection ) {
  sel = d.selection.createRange().text;
 } else if ( w.selection ) {
  sel = w.selection.createRange().text;
 } else if ( d.getSelection ) {
  sel = d.getSelection();
 } else if ( w.getSelection ) {
  sel = w.getSelection();
 }
  var f = 'http://twitter.com/home/?status='
  + e( '�y'+tid+'�z:'+sel+' '+d.title+' '+json.results[location.href]['shortUrl']+' #mjtv');
 if( !w.open(f,'retweet') ) {
  l.href = f;
 }
}