var width="780";
var height="175";
var how_many_heads = 4;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_heads;
ad +=1;

if (ad==1) {
	headurl="filestore/headerrev.jpg";
}
if (ad==2) {
	headurl="filestore/headerfisk.jpg";
}
if (ad==3) {
	headurl="filestore/headerelefant.jpg";
}
if (ad==4) {
	headurl="filestore/headerhone.jpg";
}

document.write('<img src=\"' + headurl + '\" width=')
document.write(width + ' height=' + height + ' \">');