function abrirPag(valor){  
var url = valor;  
  
xmlRequest.open("GET",url,true);  
xmlRequest.onreadystatechange = mudancaEstado;  
xmlRequest.send(null);  
  
if (xmlRequest.readyState == 1) {  
document.getElementById("conteudo_mostrar").innerHTML = "<br><br><br><br><br><center><img src='loader.gif'></center>";  
}  
  
return url;  
}  
  
function mudancaEstado(){  
if (xmlRequest.readyState == 4){  
document.getElementById("conteudo_mostrar").innerHTML = xmlRequest.responseText;  
}  
}


var randnum = Math.random();
var inum = 5;
// Change this number to the number of images you are using.
var rand1 = Math.round(randnum * (inum-1)) + 1;
images = new Array
images[1] = "backgrounds/1.gif"
images[2] = "backgrounds/02.gif"
images[3] = "backgrounds/3.gif"
images[4] = "backgrounds/4.gif"
images[5] = "backgrounds/5.gif"
var image = images[rand1]
// Deactivate cloaking device -->
<!-- Activate cloaking device
document.write('<body background="' + image + '" text="black">')
// Deactivate cloaking device -->