var XmlRequest, IDElemento;

	function requestHttp(metodo, url, id, form) {
		XmlRequest = null;
		IDElemento = id;

		// método para Mozilla
	    if (window.XMLHttpRequest) {
	    	XmlRequest = new XMLHttpRequest();
	    // método para Internet Explorer
	    } else if (window.ActiveXObject) {
			XmlRequest = new ActiveXObject("Microsoft.XMLHTTP");
	    }
	    
	    XmlRequest.open(metodo, url, true);
		XmlRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		XmlRequest.onreadystatechange = executarRequest;

		post = setPost(form);

		XmlRequest.send(post);
	}
	
	function setPost(form) {
		if (form != null) {
			result = "";
			
			for(i=0; i<form.length; i++) {
				if(result != "") {
					result += "&";
				}
				if (form[i].type == "radio") {
					if (form[i].checked == true) {
						result += form[i].name + "=" + form[i].value;
					}
				} else {
					result += form[i].name + "=" + form[i].value;
				}
			}
			
		} else {
			result = null;
		}
		
		return result;
	}
	
	function executarRequest() {
		if (XmlRequest.readyState == 4) { // Completo 
	        if (XmlRequest.status == 200) { // resposta do servidor OK
		        resposta = XmlRequest.responseText;
		        document.getElementById(IDElemento).innerHTML = resposta;
        	} else { 
            	alert("Problema: " + XmlRequest.statusText);
	        } 
    	} else
    		document.getElementById(IDElemento).innerHTML = "Carregando...";
	}