function TrocaBanner1() { 

var x = 1; 
x = Math.floor(Math.random()*3); 

if(x == 1){
document.write('<a href="http://www.ecocenter-diagmagem.com.br" target="_blank"><img border="0" src="images/banner/ecocenter_160x60.jpg" alt="Ecocenter" width="160" height="60"></a>'); 
}
else 
{ 
if(x == 2){
document.write('<img border="0" src="images/banner/banner160x60_sanatorio3.gif" alt="Hospital Clínica de Correas" width="160" height="60">'); 
}
else 
{ 
document.write('<img border="0" src="images/banner/obelisco_160x60.gif" alt="Óticas Obelisco" width="160" height="60">'); 
}}}