CSS Menu disappear

I created a menu in html/css but where I wanted the subitems to be shown on parent item hover. The problem is when I hover on it in IE it only shows it's subitems when I hover on the text in the menu item, If I hover over the element and not the text the subitems disappear again. So if I hover and want to move my mouse to my submenu the submenu disappears unless I'm fast enough. This is very annoying, does anyone know how I can solve this?

MY menu code is like so:

<ul id="leftnav">
 <li><a>Item1</a></li>
     <ul>
         <li><a href='#'>SubItem1</a></li>
         <li><a href='#'>SubItem2</a></li>
         <li><a href='#'>SubItem3</a></li>
    </ul>
 <li><a>Item2</a></li>
 开发者_如何学JAVA    <ul>
         <li><a href='#'>SubItem1</a></li>
         <li><a href='#'>SubItem2</a></li>
         <li><a href='#'>SubItem3</a></li>
     </ul>
</ul>

The menu should be a left sided menu which shows it's subitems only on hover, so I used css to achieve this with the following code:

#leftnav, #leftnav ul
{
 padding: 0;
 margin: 0;
}

#leftnav ul li
{
 margin-left: 102px;
 position: relative;
 top: -19px; /*sets the childitems on the same height as the parent item*/
}

#leftnav li
{
 float: left;
 width: 100px;
}

#leftnav ul
{
 position: absolute;
 width: 100px;
 left: -1000px; /*makes it disappear*/
}

#leftnav li:hover ul, #leftnav li.ie_does_hover ul
{
 left: auto;
}

#leftnav a
{
 display: block;
 height: 15px;
 margin-top: 2px;
 margin-bottom: 2px;
}

Since this only works with firefox I also had to insert a javascript to get this to work in IE using code:

<script language="JavaScript">
 sfHover = function()
 { 
  var sfElsE = document.getElementById("leftnav").getElementsByTagName("LI");
  for (var i=0; i<sfElsE.length; i++)
  {
   sfElsE[i].onmouseover=function()
   {
    this.className+=" ie_does_hover";
   }
   sfElsE[i].onmouseout=function()
   {
    this.className=this.className.replace(new RegExp(" ie_does_hover\\b"), "");
   }
  }
 }
 if (window.attachEvent) window.attachEvent("onload", sfHover);
</script> 

Many many many thanks for replies

In your CSS you have:

#leftnav li:hover ul

Which would mean the rule is applied to ul elements that are children of li elements when that parent li is hovered.

But in your HTML, you have:

<li><a>Item2</a></li>
    <ul>
        <li><a href='#'>SubItem1</a></li>
   </ul>

So the sub item ul is not a child of the item ul, so that rule never comes true. You need to make the sub-items nested to the items. Like this:

<ul id="leftnav">
   <li><a>Item1</a>
       <ul>
           <li><a href='#'>SubItem1</a></li>
           <li><a href='#'>SubItem2</a></li>
           <li><a href='#'>SubItem3</a></li>
      </ul>
   </li>
   <li><a>Item2</a>
       <ul>
            <li><a href='#'>SubItem1</a></li>
            <li><a href='#'>SubItem2</a></li>
            <li><a href='#'>SubItem3</a></li>
      </ul>
   </li>
</ul>

Notice how I don't close the list item until after the sub-list.

Reinventing the wheel: http://www.htmldog.com/articles/suckerfish/ teaches you about it. They even have a great example.