banner = shuffle(banner);
for(n=0;n<banner.length;n++){
document.write("<a href='",banner[n][0],"'",banner[n][3],"><img src='",banner[n][1],"' alt='",banner[n][2],"' style='border:1px solid blue;'></a>");
}

function shuffle(list) {
  var i = list.length;

  while (--i) {
    var j = Math.floor(Math.random() * (i + 1));
    if (i == j) continue;
    var k = list[i];
    list[i] = list[j];
    list[j] = k;
  }
  return list;
}