var banner = new Array();

banner.push('https://servimg.com/image_preview.php?i=1197&u=15355807');
banner.push('https://servimg.com/image_preview.php?i=1198&u=15355807');
banner.push('https://servimg.com/image_preview.php?i=1199&u=15355807');
banner.push('https://servimg.com/image_preview.php?i=1200&u=15355807');


document.getElementById('pun-logo').firstChild.src= banner[Math.floor(Math.random()*banner.length)];