function ajaxForm(strURL, formname, responsediv, responsemsg)
{
    var xmlHttpReq = false;
    var self = this;
	
    // XHR para Mozilla/Safari/Ie7
    if (window.XMLHttpRequest) 
	{
        self.xmlHttpReq = new XMLHttpRequest();
    }
	
    // Para todas as outras versões do IE
    else if (window.ActiveXObject) 
	{
        self.xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
    }
	
    self.xmlHttpReq.open('POST', strURL, true);
    self.xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    self.xmlHttpReq.onreadystatechange = function() 
	{
        if (self.xmlHttpReq.readyState == 4) 
		{
			// Quando estiver pronto, eu recebo a resposta do formulário
            updatepage(self.xmlHttpReq.responseText, responsediv);
        }
		else
		{
			// Enquanto se aguarda a resposta da forma exibida a mensagem em espera
			updatepage(responsemsg, responsediv);
		}
    }
	
    self.xmlHttpReq.send(getquerystring(formname));
}

function getquerystring(formname) 
{
    var form = document.forms[formname];
	var qstr = "";

    function GetElemValue(name, value) 
	{
        qstr += (qstr.length > 0 ? "&" : "")
             + escape(name).replace(/\+/g, "%2B") + "="
             + escape(value ? value : "").replace(/\+/g, "%2B");
		   //+ escape(value ? value : "").replace(/\n/g, "%0D");
    }
	
	var elemArray = form.elements;
	
    for (var i = 0; i < elemArray.length; i++) 
	{
        var element = elemArray[i];
        var elemType = element.type.toUpperCase();
        var elemName = element.name;
        if (elemName) 
		{
            if (elemType == "TEXT"
             || elemType == "TEXTAREA"
             || elemType == "PASSWORD"
			 || elemType == "BUTTON"
			 || elemType == "RESET"
			 || elemType == "SUBMIT"
			 || elemType == "FILE"
			 || elemType == "IMAGE"
			 || elemType == "HIDDEN")
                GetElemValue(elemName, element.value);
            else if (elemType == "CHECKBOX" && element.checked)
                GetElemValue(elemName, 
                    element.value ? element.value : "On");
            else if (elemType == "RADIO" && element.checked)
                GetElemValue(elemName, element.value);
            else if (elemType.indexOf("SELECT") != -1)
                for (var j = 0; j < element.options.length; j++) 
				{
                    var option = element.options[j];
                    if (option.selected)
                        GetElemValue(elemName,
                            option.value ? option.value : option.text);
                }
        }
    }
    return qstr;
}

function updatepage(str,responsediv)
{
    document.getElementById(responsediv).innerHTML = str;
}