[Zope] REQUEST.set not incrementing

[Jerry.Spicklemire@IFLYATA.COM]

Hi Gurus, & Newbies,

The DTML code below is intended to allow me to increment counts of logged in
users, from rows in a table. It looks like example code I've tracked down in
old mail archives, but it doesn't work. Any ideas?

<dtml-with "REQUEST.set('z_t', _.string.split(_.str(ZopeTime()))[0])">
<dtml-let u_all="_.string.atoi('0')" u_logged="_.string.atoi('0')"
u_today="_.string.atoi('0')" n_incr="_.string.atoi('1')">
 <dtml-var u_all> <dtml-var u_logged> <dtml-var u_today><br>
 <dtml-in count_users_logged>
  <dtml-call "REQUEST.set('u_all',_.int(u_all)+1)">
  <dtml-if logged_on>
   <dtml-call "REQUEST.set('u_logged',_.int(u_logged)+1)">
   <dtml-if "z_t==_.string.split(_.str(_.DateTime(logged_on)))[0]">
    <dtml-call "REQUEST.set('u_today',_.int(u_today)+1)">
   </dtml-if>
  </dtml-if>
 </dtml-in>
users_with_access = <dtml-var u_all> <br>
users_logged_ever = <dtml-var u_logged> <br>
users_logged_today = <dtml-var u_today> <br>
</dtml-let>
</dtml-with>

Thanks for taking a look.
Jerry S.