Background Image to widget area

Hi team

Can you recommend a plugin to install a custom image background to a widget?
In http://konxlink.com/book-online/, im trying to get the right hand primary widget to have a custom background. Ive tried the
background-image: url('wp-content/uploads/2014/04/c2.jpg'); code and that didnt work either when i tried to specify it to that widget i.e .sidebar .widget.

Thanks in advance!
Paul