show image in front of menu item

[CGG]

I would like to show my image when I hover over the menu in front of the menu item, now it show the image but don't display the menu item.

see my code

<style type="text/css">
.suckerdiv ul{
margin: 0;
padding: 0;
list-style-type: none;
width: 100px; /* Width of Menu Items */
border-bottom: 1px solid #ccc;
font:normal 9pt arial;
}

.suckerdiv ul li{
position: relative;
}

/*Sub level menu items */
.suckerdiv ul li ul{
font:normal 9pt arial;
position: absolute;
width: 170px; /*sub menu width*/
top: 0;
visibility: hidden;
}

/* Sub level menu links style */
.suckerdiv ul li a{
display: block;
overflow: auto; /*force hasLayout in IE7 */
color: black;
text-decoration: none;
background: #fff;
padding: 1px 5px;
border: 1px solid #ccc;
border-bottom: 0;
}

.suckerdiv ul li a:visited{
color: black;
}

.suckerdiv ul li a:hover{
font-weight: bold;
color: #FFFFFF;
background: url('arrow.jpg') no-repeat;
}

.suckerdiv .subfolderstyle{
background: url(media/arrow-list.gif) no-repeat center right;
}


/* Holly Hack for IE \*/
* html .suckerdiv ul li { float: left; height: 1%; }
* html .suckerdiv ul li a { height: 1%; }
/* End */

</style>

<script type="text/javascript">

var menuids=["suckertree1"] //Enter id(s) of SuckerTree UL menus, separated by commas

function buildsubmenus(){
for (var i=0; i<menuids.length; i++){
var ultags=document.getElementById(menuids[i]).getElementsByTagName("ul")
for (var t=0; t<ultags.length; t++){
ultags[t].parentNode.getElementsByTagName("a")[0].className="subfolderstyle"
if (ultags[t].parentNode.parentNode.id==menuids[i]) //if this is a first level submenu
ultags[t].style.left=ultags[t].parentNode.offsetWidth+"px" //dynamically position first level submenus to be width of main menu item
else //else if this is a sub level submenu (ul)
ultags[t].style.left=ultags[t-1].getElementsByTagName("a")[0].offsetWidth+"px" //position menu to the right of menu item that activated it
ultags[t].parentNode.onmouseover=function(){
this.getElementsByTagName("ul")[0].style.display="block"
}
ultags[t].parentNode.onmouseout=function(){
this.getElementsByTagName("ul")[0].style.display="none"
}
}
for (var t=ultags.length-1; t>-1; t--){ //loop through all sub menus again, and use "display:none" to hide menus (to prevent possible page scrollbars
ultags[t].style.visibility="visible"
ultags[t].style.display="none"
}
}
}

if (window.addEventListener)
window.addEventListener("load", buildsubmenus, false)
else if (window.attachEvent)
window.attachEvent("onload", buildsubmenus)

</script>


<div class="suckerdiv">
<ul id="suckertree1">
<li><a href="#">Computers</a>
<ul>
<li><a href="#">by Computer</a></li>
<li><a href="#">by Logon user</a></li>
<li><a href="#">by Data-time</a></li>
</ul>
</li>
<li><a href="#">Search</a>
<ul>
<li><a href="#">Where user is logged on</a></li>
<li><a href="#">Computer</a></li>
<li><a href="#">by Ip address</a></li>
</ul>
</li>
<li><a href="#">Folder 2</a>
<ul>
<li><a href="#">Sub Item 2.1</a></li>
<li><a href="#">Folder 2.1</a>
<ul>
<li><a href="#">Sub Item 2.1.1</a></li>
<li><a href="#">Sub Item 2.1.2</a></li>
<li><a href="#">Sub Item 2.1.3</a></li>
<li><a href="#">Sub Item 2.1.4</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>