Fatal Error : call to a member function getCfg () on a non-object

Hi i have uploaded a template on a website i have created using joomla and when i apply the template and visit my website i get the following开发者_如何学C error,

Fatal Error : call to a member function Fatal Error : call to a member function getCfg () on a non-object in /home/a7751589/public_html/templates/themza_j15_11/index.php on line 21.

the code on the index.php line 21 is as below.

$sliderVars['directionNav']=($this->params->get('sliderVars_directionNav')==='true' or $this->params->get('sliderVars_directionNav')==='false')?$this->params->get('sliderVars_directionNav'):'true';

please advise what i need to do to make this work,

Thank you

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i recommend to checking compatibility of your theme with components...

check its http://forum.joomla.org/viewtopic.php?t=637126

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Agree with GkDreamz - the "...J15..." part in your template name makes me think it's a 1.5 template that you're probably installing on a new 2.5 version.

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When this happened to me, I noticed this in the PHP script:

global $mainframe;

Bear in mind that starting with Joomla 2.5, $mainframe is no longer using global, so it should be this:

$mainframe = & JFactory::getApplication();