CGCalendar - EventTitle as PageTitle in Detail Page - tried usual, not working

[vladgarner]

Am using CGCalendar.  Trying to make the Page TITLE tag be the event title.  Have tried the following:
In the CGCalendar-Event Details Template I place:
{assign var='pagetitle' value=$event.event_title}
(this works as I use the $pagetitle within the template - it seems to work properly.

In the Template of the page I call for details, I put the following in the header- between the
{if isset($pagetitle)}
{$pagetitle}
{else}
{title}
{/if}

Problem:  Title remains the title of the page I call for details, and $pagetitle is never set.
Using: CMSMS 1.8.2, CGCalendar 1.5.5, CGExtensions 1.19.5. 

I thought the Body was sent through Smarty, then then the Header - is this the wrong locations to put this logic?  What else should I look for to troubleshoot.

Thanks,
Vlad