create template include like "$footer"

[Ghostt]

Hello,
i want to show the Forum sidebar also in the forumdisplay.php and showtherad.php and not only in forumhome..

i have created allready a template and pasted the sidebar code there.
now i want it include i to the templates forumhome dorumdisplay and showtheard like the "$footer"

the template name of my sidebar is "sidebar"
if i use $sidebar
its not apear... i think there is a shortcut or so missing that the "$sidebar" code work

you understand what i mean?