function Ajax(url, metodo, params, funcao, modo) {
	this.url = url;
	this.metodo = (metodo) ? metodo : "GET";
	this.params = (metodo=="GET") ? null : params;
	this.processaresultado = funcao;
	this.modo = (modo) ? modo : "T";
	if (this.modo != "T" && this.modo != "X") this.modo = "T";
	this.Conectar();
}
Ajax.prototype = {
	Conectar: function(){
		if (this.url == undefined || this.url == "") return;
		this.httprequest = null;
		if (window.XMLHttpRequest) // Mozilla e Safari
			this.httprequest = new XMLHttpRequest();
		else if (window.ActiveXObject) // IE
			try { this.httprequest = new ActiveXObject("Msxml2.XMLHTTP") }
			catch (e) {
			try { this.httprequest = new ActiveXObject("Microsoft.XMLHTTP");}
			catch (e) {} }
		if (this.httprequest != null && this.httprequest != undefined) {
			var obj = this;
			this.httprequest.onreadystatechange = function() { obj.processaretorno.call(obj); }
			this.httprequest.open (this.metodo, this.url + "&" + (new Date().getTime()), true);			
			this.httprequest.send (this.params);
		}
	},
	processaretorno: function(){
		if (this.httprequest.readyState == 4) {
			if (this.httprequest.status == 200) {
				var resp = (this.modo == "T") ? this.httprequest.responseText : this.httprequest.responseXML;
				if (this.processaresultado != null)
					this.processaresultado (resp);
				else
					document.write (resp);
			}else
				this.processaerro();
		}
	},
	processaerro: function(){
		alert(this.httprequest.status + ' - ' + this.httprequest.statusText + ' :-> ' + this.url);
	}
}