file upload: Browser bug, HTML bug or PHP bug?

I am noticing that when using netscape 4.7, I cannot use <input type="file" name="userfile" value="somefile.txt"> The browser will display an empty field. Perhaps this is because somefile.txt doesn't exist. OTOH, I am using the php $userfile_name variable to populate the value attribute, and php seems to strip off the directory part of the name. Is this a feature? Anyway, I'd like to know if there is a way to properly populate the value attribute. Thanks in advance for any pointer - please CC me to any replies, as I'm not subscribed to php-help. -- cg