if(!url)
{
 var url=window.location.href;
}
if(!size)
  var size="big";
var height="75";
var width="54"
if(size=="small")
{
  height="22";
  width="120";
}
if(!username)  
  var username="none";
url=url.replace("?", "*");
var src="http://www.retweet.com/widget/button/"+size+"/"+username+"/"+url;
document.write('<iframe src="'+src+'" height="'+height+'" width="'+width+'" frameborder="0" scrolling="no"></iframe>');