I think you meant to overlay a dropdown on an image. You can do that with css.
Keep the style for image as relative and absolute for dropdown, something like, change the top/left for dropdown accordingly
<head>
<style>
.image
{
position: relative;
top: 0;
left: 0;
}
.dropdown
{
position: absolute;
top: 60px;
left: 80px;
}
</style>
</head>