//AJAX DOS CLIENTES
function ajax_clientes(url)
{
//carregando
document.getElementById('pagina').style.display = 'none';
document.getElementById('carregando').style.display = '';

req = null;

if (window.XMLHttpRequest) {
req = new XMLHttpRequest();
req.onreadystatechange = processReqChange;
req.open("GET",url,true);
req.send(null);

} else if (window.ActiveXObject) {
req = new ActiveXObject("Microsoft.XMLHTTP");
if (req) { 
req.onreadystatechange = processReqChange;
req.open("GET",url,true);
req.send();
}
}
}
function processReqChange()
{ 
// apenas quando o estado for "completado"
if (req.readyState == 4) {
// apenas se o servidor retornar "OK"
if (req.status ==200) {

document.getElementById('pagina').innerHTML = req.responseText;
document.getElementById('pagina').style.display = '';
document.getElementById('carregando').style.display = 'none';

} else {
alert(req.statusText);
}
}
}