[oasi]

I'm not been able to reproduce the link stuff you mentioned, but This version could solve this stuff and the related with the &

Please, try it and let me know...

<script type="text/javascript">
function checkURL()
  {
      if ((url.indexOf("http://")!=url.lastIndexOf("http://"))||url.lastIndexOf("http://")!=0){return false;}
      if (url.indexOf('"')>=0) {return false;}
      if (url.indexOf("http://maps.google")!=0){return false;}
      return true
  }

tot='';
tot_ini='{param}';
tot_no_amp=tot_ini.replace(/&amp;/g,'&');
tot_no_quo=tot_no_amp.replace(/&quot;/g,'"');
tot=tot_no_quo.substr(tot_no_quo.indexOf('marginwidth="0" src="')+21,tot_no_quo.length);
url=tot.substr(0,tot.indexOf('"'));
urlp=url.replace(/amp;/g,'');
url=urlp;

if (checkURL())
{   
    document.write('<iframe width="640" height="480" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="'+url+'"></iframe>');
}
else
{
document.write("<p><b>WRONG URL</b></p>Recorda que cal enganxar el contingut del camp que indica que es per enganxar en una web.<br />Un cop arreglat el post, has de recarregar la plana per poder veure si ha funcionat.");
}
</script>

If this fails, and the error message appears, please view source on the document and paste here the value for the variable tot_ini ( Right click on document, View source, search tot_ini)

Thanks