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];
}