function getTagString()
{
  var regex = new RegExp("tag/([^&#]*)");
  var qs = regex.exec(window.location.href);
    
  if(qs == null)
    return null;
  else
    return qs[1];

}

function getQuerystring(key, default_)
{
  if (default_==null) default_="";
  
  key = key.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
  var regex = new RegExp("[\\?&]"+key+"=([^&#]*)");
  var qs = regex.exec(window.location.href);
  
  if(qs == null)
    return default_;
  else
    return qs[1];

}