var banner = new Array();

banner.push('https://img11.hostingpics.net/pics/838567headershaycopie.png');
banner.push('https://img11.hostingpics.net/pics/990317headerfreyacopie.png');
banner.push('https://img11.hostingpics.net/pics/185670headerbonniecopie.png');
banner.push('https://img11.hostingpics.net/pics/983751headerdiannacopie.png');

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