images = new Array(5);

images[0] = "<div id='header_sms'><a href='http://sms.hostiran.net' title='sms.hostiran.net'><h1>SMS</h1></a></div>";

images[1] = "<div id='header_design'><a href='http://design.hostiran.net' title='design.hostiran.net'><h1>Design</h1></a></div>";

images[2] = "<div id='header_in'><a href='http://3800.ir' title='3800.ir'><h1>IN</h1></a></div>";

images[3] = "<div id='header_uptime'><a href='http://siteuptime.ir' title='siteuptime.ir'><h1>Uptime</h1></a></div>";

images[4] = "<div id='header_help'><a href='http://help.hostiran.net' title='help.hostiran.net'><h1>Help</h1></a></div>";

index = Math.floor(Math.random() * images.length);

document.write(images[index]);