terminate loop when etarget is falsy
terminate loop when etarget is falsy

clicking the document will fire the event on the HTML object and not
on the BODY object.  This will result in the loop terminating on error
when etarget becomes null

lognormal/boomerang,forcedotcom/kylie,lognormal/boomerang,levexis/boomerang,sdgdsffdsfff/boomerang,levexis/boomerang,sdgdsffdsfff/boomerang,forcedotcom/kylie,FredXue/boomerang,FredXue/boomerang