var url = parent.document.URL;
var loc = url.substring(url.indexOf('?')+8, url.length); 
var ref = loc.replace(/\/.*/g, "");
document.write('<a hr'+'ef="ht'+'tp://w'+'ww.'+'picka'+'trail'+'.com'+'/neptune/directory/america/'+'us_national_parks.html?ref='+ref+'" onClick="javascript: pageTracker._trackPageview(\'/ads/pickatrail.com/topo-maps.html\');">'+'<img src="'+'http://www.fish4travel.com/ads/images/'+'topo-maps2.gif'+'" height="55" width="354" style="border: none; margin: 0 0 12px 0"></a><br>');