APEX

Hi,

I have entered the following JS code in my page header:
<<CODE>>
<SCRIPT LANGUAGE=JAVASCRIPT TYPE="TEXT/JAVASCRIPT">
<!-- Hide script from old browsers<br>

if (document.referrer != "www.someurl.com")
location.href = "http://www.gohere.com";
//-- Stop hiding script -->
</SCRIPT>
<<ENDCODE>>

However I always get the value "undefined".
Is there anyway to check what the referer page is?

Thanks in advance.
VC