while(true){
aleatorio = Math.random();
numero = Math.round(aleatorio * 7);

if (numero == 0){
imagen = "http://img690.imageshack.us/img690/8958/madonnamia1.jpg";
break;}

if (numero == 1){
imagen = "http://img442.imageshack.us/img442/7865/madonnamia2.jpg";
break;}

if (numero == 2){
imagen = "http://img442.imageshack.us/img442/9913/madonnamia3.jpg";
break;}

if (numero == 3){
imagen = "http://img267.imageshack.us/img267/1858/madonnamia4.jpg";
break;}

if (numero == 4){
imagen = "http://img267.imageshack.us/img267/439/madonnamia5.jpg";
break;}

if (numero == 5){
imagen = "http://img267.imageshack.us/img267/1892/madonnamia6.jpg";
break;}

if (numero == 6){
imagen = "http://img42.imageshack.us/img42/683/madonnamia7.jpg";
break;}

}
document.write('<a href="http://madonnamia.foroactivo.net" target="_self" ><img src="' + imagen + '" border=0 style="width: 970px; height: 333px"></a>');