[cd34]

if you just delete the first condition, if the referrer is empty, it would do your include. My guess at your intention was to include the local code if it was a typein/bookmark or local site referrer, and include the /path/to/file.html if it was a remote referrer.

|| ($referrer=="") )

says: or, the referrer is empty

if you want to include the INSERT CODE for local hits + bookmarks/typeins, you want to use the || ($referrer=="") ) version. If you want only want to display INSERT CODE for local hits, and bookmarks/typeins/remote referrers get the /path/to/file.html, then just removing the isset() condition would do that.