var banner = new Array();

banner.push('https://img11.hostingpics.net/pics/589425fwhiskey21.png');
banner.push('https://img11.hostingpics.net/pics/863442fwhiskey41.png');
banner.push('https://img11.hostingpics.net/pics/385688fwhiskey31.png');
banner.push('https://img11.hostingpics.net/pics/622799fwhiskey11.png');

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