Question: ```
<style>
 .h,.e {list-style-type: none; float:left;}
 .h div,.e div{background-color:gray; padding:2px 20px;margin:1px;}
 #h1,#e1{background-color:yellow; padding:2px 20px;margin:5px; visibility:hidden;
 }

```

```
<ul>
  <li class="h">
    <div id="h">Home</div>
    <ul class="h1" id="h1"><li>H1</li><li>H2</li><li>H3</li><li>H4</li></ul>
  </li>
  <li  class="e">
    <div id="e">Exit</div>
    <ul class="e1" id="e1"><li>E1</li><li>E2</li><li>E3</li><li>E4</li></ul>
  </li>
<ul>

<script>
  var oh = document.getElementById("h");
  var oe = document.getElementById("e");
  var oh1 = document.getElementById("h1");
  var oe1 = document.getElementById("e1");

  oh.onmouseover=function(){oh1.style.visibility="";};
  oe.onmouseover=function(){oe1.style.visibility="";};
</script>

```

on mouseover i want to show the id=h1,e1 items but it is not working...., what is going wrong with the code?

Answer: 
Try `visible`. 

```
oh1.style.visibility="visible";

```
Try:

```
oh1.style.visibility="visible";

```

Should be a pretty obvious fix, but as for explanation - setting visibility to "" is no value - hence there will be no change, "visible" is an accepted value and will show the oh1 object.