phptemplate: How do you add variables to the page template?

I want to use the $terms variable (taxonomy terms) in the pagetemplate of phptemplate. This show in the node template in the box_grey theme so I thought just using it would be okay. Well that did not work. so I tried to add the code used in the engine to set the node variables to the page template. this did not work either.

How do you best accomplish adding variables to a template?

TIA