[Sunka]

This is work for me in vBulletin v3.8.2

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

tot='{param}';
tot=tot.substr(tot.indexOf("src=&quot;")+10,tot.length);
url=tot.substr(0,tot.indexOf("&quot;"));
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 map URL, edit the post to change it.</b></p>Reload the page when finished to check if correct.");
}
</script>