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 createXMLDOM() 
{	
	var arrSignatures = ["Microsoft.XMLDOM", "MSXML2.XMLDOM", "MSXML.XMLDOM", "MSXML3.XMLDOM"];
	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 loadXMLString(txt) 
{
	try //Internet Explorer
	{
		xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
		xmlDoc.async="false";
		xmlDoc.loadXML(txt);
		return(xmlDoc); 
	}
	catch(e)
	{
		try //Firefox, Mozilla, Opera, etc.
	    {
		    parser=new DOMParser();
		    xmlDoc=parser.parseFromString(txt,"text/xml");
		    return(xmlDoc);
		}
		catch(e) 
		{
			alert(e.message)
		}
	}
	return(null);
}