/* identifica internet explorer */
var IE = false;
if ( navigator.userAgent.toLowerCase().indexOf( "msie" ) != -1 ) { IE = true; }

/* ritorna l'elemento dell' id specifcato */
function getElemById(id) {
	var el;
	if(document.getElementById) {
		el = document.getElementById(id);
	} else {
		el = document.all[id];
	}
	return el;
}

/* crea un elemento DOM */
function createElem(element) {
	return document.createElement(element);
}

/* ritorna un oggetto XMLHttpRequest o NULL */
function newXHR() {
	var	XHRobj = null;
	var browserUtente = navigator.userAgent.toUpperCase();
	if(typeof(XMLHttpRequest) === "function" || typeof(XMLHttpRequest) === "object") {
		XHRobj = new XMLHttpRequest();
	} else if(window.ActiveXObject && browserUtente.indexOf("MSIE 4") < 0) {
		if(browserUtente.indexOf("MSIE 5") < 0) {
			XHRobj = new ActiveXObject("Msxml2.XMLHTTP");
		} else {
			XHRobj = new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	return XHRobj;
}

/* valida risposta xml */
function ajax_validate_xml(ajax) {
	if(statusText[ajax.status] === "OK") {
		if(ajax.responseXML) {
			return true;
		} else {
			alert("errore ajax: xml non valido");
		}
	} else {
		alert("errore ajax: " + statusText[ajax.status]);
	}
	return false;
}

/* elenco degli stati ajax */
var readyState = {
	INATTIVO:	0,
	INIZIALIZZATO:	1,
	RICHIESTA:	2,
	RISPOSTA:	3,
	COMPLETATO:	4
};

	
/* elenco descrittivo dei codici restituiti dal server */
var statusText = new Array();
statusText[100] = "Continue";
statusText[101] = "Switching Protocols";
statusText[200] = "OK";
statusText[201] = "Created";
statusText[202] = "Accepted";
statusText[203] = "Non-Authoritative Information";
statusText[204] = "No Content";
statusText[205] = "Reset Content";
statusText[206] = "Partial Content";
statusText[300] = "Multiple Choices";
statusText[301] = "Moved Permanently";
statusText[302] = "Found";
statusText[303] = "See Other";
statusText[304] = "Not Modified";
statusText[305] = "Use Proxy";
statusText[306] = "(unused, but reserved)";
statusText[307] = "Temporary Redirect";
statusText[400] = "Bad Request";
statusText[401] = "Unauthorized";
statusText[402] = "Payment Required";
statusText[403] = "Forbidden";
statusText[404] = "Not Found";
statusText[405] = "Method Not Allowed";
statusText[406] = "Not Acceptable";
statusText[407] = "Proxy Authentication Required";
statusText[408] = "Request Timeout";
statusText[409] = "Conflict";
statusText[410] = "Gone";
statusText[411] = "Length Required";
statusText[412] = "Precondition Failed";
statusText[413] = "Request Entity Too Large";
statusText[414] = "Request-URI Too Long";
statusText[415] = "Unsupported Media Type";
statusText[416] = "Requested Range Not Satisfiable";
statusText[417] = "Expectation Failed";
statusText[500] = "Internal Server Error";
statusText[501] = "Not Implemented";
statusText[502] = "Bad Gateway";
statusText[503] = "Service Unavailable";
statusText[504] = "Gateway Timeout";
statusText[505] = "HTTP Version Not Supported";
statusText[509] = "Bandwidth Limit Exceeded";


/* apre una url */
function openURL(url) {
	setTimeout("document.location.href ='"+(url)+"'",100)
	return true;
}