bookmarklet to submit to youtube downloader script

bookmarkelt.js

javascript:(function(){

  serverUrl = 'http://example.com/youtubedl.php';

  re = /^https?:\/\/www\.youtube\.com\/watch\?v=([\w-]+)/;
  
  
  if(matches = re.exec(location.href)) {
    videoId = matches[1];
    var form = document.createElement("form");
    form.setAttribute("method", 'post');
    form.setAttribute("action", serverUrl);
    
    var field = document.createElement("input");
    field.setAttribute("type", "hidden");
    field.setAttribute("name", 'url');
    field.setAttribute("value", videoId);
    form.appendChild(field);
    
    document.body.appendChild(form);
    form.submit();
  } else {
    alert('Invalid page: not a youtube video page');
  }
  
  
})();