// JavaScript Document
y = 0;
ad = new Array(y);
ad[y++] = '<img src="topo/1.jpg" border="0"></a>'
ad[y++] = '<img src="topo/2.jpg" border="0"></a>'
ad[y++] = '<img src="topo/3.jpg" border="0"></a>'
ad[y++] = '<img src="topo/4.jpg" border="0"></a>'
ad[y++] = '<img src="topo/5.jpg" border="0"></a>'
ad[y++] = '<img src="topo/6.jpg" border="0"></a>'
ad[y++] = '<img src="topo/7.jpg" border="0"></a>'

x = Math.floor(Math.random()*(y));
document.write(ad[x])