var banner = new Array();

banner[0]='https://nsa33.casimages.com/img/2013/04/26/130426064010169626.png';
banner[1]='https://nsa34.casimages.com/img/2013/04/26/130426064040868823.png';
banner[2]='https://img15.hostingpics.net/pics/697589exc.png';
banner[3]='https://nsa33.casimages.com/img/2013/05/04/130504110650170086.png';
banner[4]='https://nsa34.casimages.com/img/2013/05/09/130509040559340702.png';
banner[5]='https://img11.hostingpics.net/pics/456174HeaderEC3.png';
banner[6]='https://img11.hostingpics.net/pics/648727HeaderEC4.png';

document.getElementById('i_logo').src= banner[Math.floor(Math.random()*banner.length)];