Wite Frame in webGL

I just finished my first game, following tutorial, and modifying it.
Made it into webGl , - which was not tutorials target build
and now after i placed it on website there is a hudge white frame with unity logo, and alot of empty space.

My question is : how to get rid of that white empty space?

It can be seen at :
http://www.irs.net.pl/
by frame i mean all that white space surronding game screen if not maximazed.
Is it something i may set up in unity?