How to add a Close button/icon in the banner of HTML 5 viewer?

Hi,

 

Does there a way to add a Close button/icon in the banner of HTML 5 viewer?

 

Or application embeded the viewer as part of a page. And want to give user a way to clsoe that DIV includes the viewer. Since the viewer takes the whole Div, so the best way is to have a Close button at top-right corner in the viewer.

 

James