// JavaScript Document

        var http = getXmlHttpRequestObject();


        function getXmlHttpRequestObject()
        {
            var http_request = false;

            if (window.XMLHttpRequest)
            { // Mozilla, Safari,...
                browser ='mozilla';
                http_request = new XMLHttpRequest();
                if (http_request.overrideMimeType)
                {
                    http_request.overrideMimeType('text/xml');
                    // See note below about this line
                }
            }
            else if (window.ActiveXObject)
            { // IE
                browser ='ie';
                try
                {
                    http_request = new ActiveXObject("Msxml2.XMLHTTP");
                }
                catch (e)
                {
                    try
                    {
                        http_request = new ActiveXObject("Microsoft.XMLHTTP");
                    } 
                    catch (e2) 
                    { 
                        //nothing
                    }
                }
            }

            if (!http_request)
            {
                alert('Giving up : Cannot create an XMLHTTP instance');
                return false;
            }

            return http_request;
        }
        function load(url)
        {
			http.open("GET",url,true);
			var postData = '';
			http.onreadystatechange = resposta;
			http.setRequestHeader("Content-Type","application/x-www-form-urlencoded; charset=UTF-8");
			http.send(postData);
        }
        
        function resposta()
        {
            if(http.readyState == 4)
            {
                if (http.status == 200)
                {
					var obj = http.responseText;
					element = document.getElementById('principal');
					var init = obj.indexOf('<principal>')+11;
					var end  = obj.indexOf('</principal>');
					var temp = obj.substring(init, end);
					element.innerHTML = temp;
                }
                else
                {
                    alert(http.status + ' - Error Loading page.');
                }
            }
        }