php HTML安全过滤

  /*HTML安全过滤*/
        function _htmtocode($content) {
                $content = str_replace('%','%‎',$content);
                $content = str_replace("<", "&lt;", $content);
                $content = str_replace(">", "&gt;", $content);
                $content = str_replace("\n", "<br/>", $content);
                $content = str_replace(" ", "&nbsp;", $content);
                $content = str_replace('"', "&quot;", $content);
                $content = str_replace("'", "'", $content);
                $content = str_replace("$", "$", $content);
                $content = str_replace('}','&rlm;}',$content);
                return $content;
        }