function GetXMLHttp() {

    if(navigator.appName == "Microsoft Internet Explorer") {

        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");

    }

    else {

        xmlHttp = new XMLHttpRequest();

    }

    return xmlHttp;

}


var xmlRequest = GetXMLHttp();

function abrirPag(valor){

var url = valor;


xmlRequest.onreadystatechange = mudancaEstado;

xmlRequest.open("GET",url,true);

xmlRequest.send(null);


if (xmlRequest.readyState == 1) {

document.getElementById("conteudo").innerHTML = "<center><br><img src='imagens/load.gif'><br>Carregando conteúdo...<br><br></center>";

}


return url;

}


function mudancaEstado(){

if (xmlRequest.readyState == 4){

document.getElementById("conteudo").innerHTML = xmlRequest.responseText;

}

}