<script language="javascript">

     function moveon(id) {



         bolck = document.getElementById(id).style;

         bolck.visibility = "visible";



     }

     function moveout(id) {

         bolck = document.getElementById(id).style;

         bolck.visibility = "hidden";



     }

        </script>

<ul class="sec_nav"><li>

<a href="###" onmousemove="moveon('sx')" onmouseout="moveout('sx')">AAA</a></li>

</ul>

<div id="sx" class="threeblock">

 

</ul></div>

<ul class="sec_nav"><li>

<a href="###" onmousemove="moveon('sx')" onmouseout="moveout('sx')">AAA</a></li>

</ul>

<div id="sx" class="threeblock" style="border:solid 1px black" onmouseover="moveon(this.id)" onmouseout="moveout(this.id,true)">

 sx</div>

 <script language="javascript">

     var timers = {}

     function moveon(id) {

         clearTimeout(timers[id]);

         bolck = document.getElementById(id).style;

         bolck.visibility = "visible";



     }

     function moveout(id, im) {

         if (im) {

             bolck = document.getElementById(id).style;