Button in Fluid UX view

Is there a way to place a button in the new Polaris Fluid UX view that will open a window.  My old javascript (that works in classic view)  seems to push the views to the "classic" view when I add my lib to the onload event of the form.  I then tried a silverlight solution but couldn't get the new view to recognize it.  Anyone have a link on how to do this?

Thanks,

LLB

WeDoMapping