how to make "tweet" button active in Twitter Anywhere TweetBox

Question

I added a Twitter Anywhere TweetBox to my blog maxim.tumblr.com like this:

var idvar = "tweetbox"; twttr.anywhere(function (T) { T("#tweetbox").tweetBox({ label: "Tweet me:", height: 100, width: 210, defaultContent: "@maxgrinev Hello!", onTweet: function (tweet, htmlTweet) { document.getElementById(idvar).setAttribute("style", "display: none;"); } }); });

Everythink works fine except the tweet button is not active by default. You have to edit the box to make it active (look here: http://maxgrinev.tumblr.com/). How can I make it active by default?