Aligning a div underneath & horizontaly central an element

[CyberXZT]

Let's say I have a context menu that goes like this\[code\] |here|there|somewhere|\[/code\]which is simple \[code\]<ul> <li>here</li> ...<ul>\[/code\]with and onclick I want to add a div with an image like this:\[code\] |here|there|somewhere| ^\[/code\]Aligned horizontally in the middle of the element, vertically underneath it. How can I do it?