critique this code please

i have this small function for a template system (if you want to call it that ;) my idea was having something simple to separate html code from php and i think using something like smarty is too big for me and i really dont have time to learn to use it. so i have this code here: http://www.cstrike-planet.com/function.phps i call this function which reads .tpl files which contain html and some $vars, then in my pages use something like: eval('echo("' . template('home_index') . '");'); unfortunaly my site has grown since and im not sure if this is causing an extra overhead on the site.. is there a way to 'improve' this small function? thanks for any help.