Hi, We are passing our signup links to the https://secure.doman.com/nbilling/(file.php)?parameteres Code (markup): We want to have a URLrewriter for above to add extra parameter "systpl=newdom1". So whatever request comes to https://secure.doman.com/nbilling/ shuld check the HTTP_REFERER and if its equal to newdomain1.com then it should add "systpl=newdom1" to this URL. For example https://secure.doman.com/nbilling/(anyfile.php)?systpl=newdom1&(anyparameteres Code (markup): likewise if the request coming from newdomain2.com then it should add systpl=newdom2 I tried the below code but it didn't work. can you guy pls check and let me know whats wrong I am doing ? RewriteCond %{HTTP_REFERER} ^$ RewriteCond %{HTTP_REFERER} ^http://newdomain1.com/.*$ [OR,NC] RewriteCond %{HTTP_REFERER} ^http://www.newdomain1.com.com/.*$ [OR,NC] RewriteRule ^(.*)$ https://secure\.domain\.com/nbilling/$1?systpl=rhs [QSA,L,R=301]