Ok, here's the thing. Whos_online.html's HTML Table structure is not under any
while loop statement. Meaning, the username only appears in one whole table presentation and is, defaultly, seperated with commas under includes/sessions.php file (to make seperations of each usernames from a single TD alignment).
Meaning, in order to accomplish your request, you would NOT be able to make any modifications under whois_online.html file since the HTML Table will have to be re-coded from includes/sessions.php file
entirely.
That said, are you sure you wish to have this ? Since you will be limited to edit your HTML file after this.
Please advise.
[EDIT]
OR, I don't know (yet) if this can be done but, by simply adding the TD alignment as part of the while loop then register that new related string to the whois_online.html, perhaps it could work. Althought, I can't be a 100% sure on this one since I did not tested this before.