center image in dashboard widget

I am trying to center an image in a dashboard widget. Arun gave me this code
https://premium.wpmudev.org/forums/topic/image-resize-in-a-box

The image resizes nicely but does not center in the dashboard widget.
How do I get it to center?

<p style="text-align: center;"><div class="imagebox"><img class="aligncenter size-full" title="" src="http://mydomain.com/wp-content/uploads/2012/04/stuff-wholesale.jpg" alt="" /></div></p>