joomla1.5 - Change template after user login in joomla 1.5 -

anybody ever tried change joomla 1.5 template in code? don't know how on current version. wanted change template after user login.

so, wrote code :

$mainframe->settemplate('newtemplate'); 

but doesn't works. when see joomla application.php, whoops, there no settemplate function there, used there before 1.5 (based on search on web). know how it?

update : seems can set user state , read user state, render. don't know joomla render template, since put code in library/joomla/application.php, insite render(), didn't executed. did :

function render() {     $params = array(         'template'     => $this->gettemplate(),         'file'        => 'index.php',         'directory'    => jpath_themes     );      // added code, set user state $option.template somewhere else     $template = $mainframe->getuserstate( "$option.template", 'foxysales01vip' );     if(!empty($template)){         $params['template'] = $template;     }      $document =& jfactory::getdocument();     $data = $document->render($this->getcfg('caching'), $params );     jresponse::setbody($data); } 

never mind, solved it.

just change code in core library (jdocument class) read template session, works fine.

thanks