<!-- <sblock_nmenu> -->
<sticknav>
<?if($NMENU_1$)?>
   <!-- <bc> -->
   <B>$NMENU_1$</B>
   <!-- </bc> -->
   <?endif?>
<!-- </sblock_nmenu> -->
  </sticknav>

/* Bắt đầu Stick Nav */
sticknav {
background: #ffffff;
height: 30px;
width: 100%;
margin-right: 0px;
margin-left: 0px;
left: 0px;
right: 0px;
position: relative;
z-index: 9999999999999999;
}
.fixed { position:fixed;}
/* Kết thúc Stick Nav */

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
var aboveHeight = $('header').outerHeight();
    $(window).scroll(function(){
        if ($(window).scrollTop() > aboveHeight){
        $('sticknav').addClass('fixed').css('top','0').next().css('padding-top','60px');
        } else {
       $('sticknav').removeClass('fixed').next().css('padding-top','0');
        }
    });
});
</script>