var banner=[
"/assets/images/header.jpg",
"/assets/images/header2.jpg",
"/assets/images/header3.jpg",
"/assets/images/header4.jpg",
"/assets/images/header5.jpg",
"/assets/images/header6.jpg",
"/assets/images/header7.jpg",
];
var random=Math.floor(banner.length*Math.random());
document.write("<style type=\"text/css\">");
document.write("#header {");
document.write(' background:url("' + banner[random] + '") no-repeat 50% 0');
document.write(" }");
document.write("<\/style>");