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];
	}