function onLevel1HoverOver(event){
  target = $(event.target);
  target.next(".kl_catnav01_catlev2_bx1").show();
}

function onLevel1HoverOut(event){
  $(".kl_catnav01_catlev2_bx1").hide();
}

$(document).ready(function(){
 $(".kl_catnav01_catlev2_bx1").hide();
 $(".kl_catnav01_catlev1_bx2").hover(onLevel1HoverOver, onLevel1HoverOut);
});