Fatal error: Using $this when not in object context

Là, je suis en plein dans la programmation et je me trouve devant cette erreur:
Fatal error: Using $this when not in object context.
Et l'erreur indiquée se situerait dans cette fonction

Code:

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function tptabanimated1() {
echo "<!-- start tab 1 -->\n";
 
if (($this->countModules( 'user50' )) || ($this->countModules( 'user51' )) || ($this->countModules( 'user52' )) || ($this->countModules( 'user53' )) || ($this->countModules( 'user54' )) || ($this->countModules( 'user55' ))) { 
 
echo "<div id=\"tab1\" style=\"margin:5px;\">\n";
echo "<ul>\n";
	if ($this->countModules( 'user50' )) { 
	echo "<li><a href=\"#user50\"><span>\n";
	echo $tab1a_name;
	echo "</span></a></li>\n";
	}
	if ($this->countModules( 'user51' )) { 
	echo "<li><a href=\"#user51\"><span>\n";
	echo $tab2a_name;
	echo "</span></a></li>\n";
	}
	if ($this->countModules( 'user52' )) { 
	echo "<li><a href=\"#user52\"><span>\n";
	echo $tab3a_name;
	echo "</span></a></li>\n";
	}
	if ($this->countModules( 'user53' )) { 
	echo "<li><a href=\"#user53\"><span>\n";
	echo $tab4a_name;
	echo "</span></a></li>\n";
	}
	if ($this->countModules( 'user54' )) { 
	echo "<li><a href=\"#user54\"><span>\n";
	echo $tab5a_name;
	echo "</span></a></li>\n";
	}
	if ($this->countModules( 'user55' )) { 
	echo "<li><a href=\"#user55\"><span>\n";
	echo $tab6a_name;
	echo "</span></a></li>\n";
	}
echo "</ul>\n";
	if ($this->countModules( 'user50' )) { 
	echo "<div id=\"user50\">\n";
	echo '<jdoc:include type="modules" name="user50" style="xhtml" />';
	echo "</div>\n";
	}
 
	if ($this->countModules( 'user51' )) { 
	echo "<div id=\"user51\">\n";
	echo '<jdoc:include type="modules" name="user51" style="xhtml" />';
	echo "</div>\n";
	}
 
	if ($this->countModules( 'user52' )) { 
	echo "<div id=\"user52\">\n";
	echo '<jdoc:include type="modules" name="user52" style="xhtml" />';
	echo "</div>\n";
	}
 
	if ($this->countModules( 'user53' )) { 
	echo "<div id=\"user53\">\n";
	echo '<jdoc:include type="modules" name="user53" style="xhtml" />';
	echo "</div>\n";
	}
 
	if ($this->countModules( 'user54' )) { 
	echo "<div id=\"user54\">\n";
	echo '<jdoc:include type="modules" name="user54" style="xhtml" />';
	echo "</div>\n";
	}
 
	if ($this->countModules( 'user55' )) { 
	echo "<div id=\"user55\">\n";
	echo '<jdoc:include type="modules" name="user55" style="xhtml" />';
	echo "</div>\n";
	}
 
echo "</div>\n";
echo "<div style=\"clear:both; line-height:1px;\"> &nbsp;</div>	\n";
	}
}

Alors là, j'ai besoin de vous...

Je rappelle que cette fonction se trouve dans l'index(le <head> pour être plus précis) de mon template joomla.