Question about "Undefined variable: PHP_SELF/HTTP_HOST"

I'm new to PHP, and am adapting some code. I'm stuck with warnings due to PHP_SELF and HTTP_HOST being undefined. I inserted a phpinfo(); just before the offending lines and the output shows these two variables being defined...so what gives? code snippet: .... phpinfo(); echo "self $PHP_SELF"; echo "host $HTTP_HOST"; .... Output shows tons of phpinfo stuff, followed by: Warning: Undefined variable: PHP_SELF in c:\inetpub\wwwroot\message\admin\index.php on line 47 self Warning: Undefined variable: HTTP_HOST in c:\inetpub\wwwroot\message\admin\index.php on line 48 host Any ideas? This is PHP4 on w2k (yuck). jim - - - - - - - Appended by Scientific-Atlanta, Inc. - - - - - - - This e-mail and any attachments may contain information which is confidential, proprietary, privileged or otherwise protected by law. The information is solely intended for the named addressee (or a person responsible for delivering it to the addressee). If you are not the intended recipient of this message, you are not authorized to read, print, retain, copy or disseminate this message or any part of it. If you have received this e-mail in error, please notify the sender immediately by return e-mail and delete it from your computer.