var imagesarr = new Array(
 "/img/top_05.jpg",
 "/img/top_05.jpg",
 "/img/top_05.jpg",
 "/img/top_06.jpg"
 );

var los = Math.floor(Math.random() * imagesarr.length);
document.write ("<img src='"+imagesarr[los]+"' width='776' height='151' alt='' usemap='#header' /><map name='header'><area coords='715,-1,744,22' alt='' href='/index.php' /><area coords='743,-26,775,23' alt='' href='/en/index.php' /><area coords='616,90,772,147' alt='' href='index.php' /></map>");