function createXMLHTTP(){
	var ajax;
	try{
		ajax = new ActiveXObject("Microsoft.XMLHTTP");
	}catch(e){
	   try{
			ajax = new ActiveXObject("Msxml2.XMLHTTP");
			//alert(ajax);
		}catch(ex){
			try{
			   ajax = new XMLHttpRequest();
			}catch(exc){
				alert("Esse browser não tem recursos para uso do Ajax");
				ajax = null;
			}
		}
		return ajax;
	}


	   var arrSignatures = ["MSXML2.XMLHTTP.5.0", "MSXML2.XMLHTTP.4.0",
																  "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP",
																  "Microsoft.XMLHTTP"];
	   for (var i=0; i < arrSignatures.length; i++){
			try{
				var oRequest = new ActiveXObject(arrSignatures[i]);
				return oRequest;
			}catch (oError){}
	   }
   
	  throw new Error("MSXML is not installed on your system.");
}



function enviaPage(url, metodo, modo, tagId, parametros)
{
    goAjax( url+"?"+parametros+"&rnd"+ Math.random() , metodo, modo , tagId);
}



function goAjax(url, metodo, modo, tagRetorno, parametros) {
		var xmlhttp = new createXMLHTTP();
        document.getElementById(tagRetorno).innerHTML='<div align="center" class="carregando"><img src="../images/carregando.gif"><br /><br />carregando...</div>'

            if(metodo == "GET") {
                xmlhttp.open("GET", url, modo);
            } else {        
                xmlhttp.open("POST", url, modo);
                xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=iso-8859-1");
                xmlhttp.setRequestHeader("Cache-Control", "no-store, no-cache, must-revalidate");
                xmlhttp.setRequestHeader("Cache-Control", "post-check=0, pre-check=0");
                xmlhttp.setRequestHeader("Pragma", "no-cache");
            }    
            
            xmlhttp.onreadystatechange = function() {
                if(xmlhttp.readyState == 4) {
                    retorno=xmlhttp.responseText
					//alert(retorno);
                    document.getElementById(tagRetorno).innerHTML=retorno					
                }
            }
            if(metodo == "GET") {
                xmlhttp.send(null);
            } else {        
                xmlhttp.send(parametros);
            }
}