$stop_words=  array("I "," a "," about "," an "," are "," as "," at "," be "," by "," com "," de "," en "," for "," from "," how ","How "," in "," is"," it "," la "," of "," on "," or ","Or "," that "," the ","The "," this "," to "," was "," what "," when "," where "," who ","Who "," will "," with "," und "," the "," www ","!",".","?","=","-");

        $keywords_ = str_replace($stop_words," ",$context['page_title']);

        $keywords_ =  preg_replace ( "/ss+/" , " " , $keywords_);

        $keywords_ = str_replace(" ",", ",trim($keywords_));