how can i edit guestbook render to get {FULL_NAME}?

[fmaltez]

i need to edit my guestbook render, to create the tag "{FULL_NAME}", infortunely only {NAME} and {EMAIL} are avaliable (but i want to get also the usr_name (extended name) from user-table instead of the small usr_id)

i've look in contentpart 18, but i didnt find out where i get the QUERY from database...

i use this on my template right now:
<input name="guestbook_name" type="hidden" id="guestbook_name" class="gbInputField" value="{NAME}" size="50" maxlength="500" />

how do i use, access the user profile info... is there anything coded in phpwcms that use's that info?

the same question for usr_avatar....

thank you