check http referer
Javascript referer:
<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
if (location.href.indexOf("dev") != -1){
document.write("thank you");
}
else {
document.write("Our new address is http://come.to/......");
}
// End -->
</SCRIPT>
Perlscript in ASP referer
<%$ReferringPage = $Request->Servervariables('HTTP_REFERER')->item;%>
Perl referer
if($ENV{'HTTP_REFERER'} =~/cgi\/cgi-shell\/esp\/adapter/)