show hide div on mouseover and mouseout

Answer 1

try

<script type="text/javascript">
function show_sidebar()
{
document.getElementById('sidebar').style.display="block";
}

function hide_sidebar()
{
document.getElementById('sidebar').style.display="none";
}
</script>

<img src="images/cart.jpg" width="80px" height="30px" onMouseOver="show_sidebar()"     onMouseOut="hide_sidebar()">

<div id="sidebar">some thing</div>