导航栏支持二级菜单图标符号下拉高亮

<?php
$sql=$empire->query("select classid,classname,islast from {$dbtbpre}enewsclass where bclassid=0 and showclass=0 order by myorder,myorder asc");
    while($s=$empire->fetch($sql)){
    	$tclass="";
		$tclass2="";
        $fr=explode('|',$class_r[$GLOBALS[navclassid]][featherclass]);
        $topbclassid=$fr[1]?$fr[1]:$GLOBALS[navclassid];
        if($topbclassid==$s[classid]){
        	$tclass='active';
        }
		if(!$s[islast]){$tclass2='<i class="fa fa-angle-down"></i>';}
        $classurl=sys_ReturnBqClassname($s,9);
       
        echo '<li class="'.$tclass.'"><a href="'.$classurl.'">'.$s[classname].''.$tclass2.'</a>';
        if(!$s[islast]){
        	$sql2=$empire->query("select classid,classname from {$dbtbpre}enewsclass where bclassid=$s[classid] and showclass=0 order by myorder,myorder asc");
            $str="";
            while($s2=$empire->fetch($sql2)){
            	$classurl2=sys_ReturnBqClassname($s2,9); 

            	$str.='<li><a href="'.$classurl2.'">'.$s2[classname].'</a></li>';
            }
            echo '<ul>'.$str.'</ul>';
        }
        echo '</li>';
    }
?>