var Win=navigator.userAgent.indexOf("Win")!=-1;	
var Mac=navigator.userAgent.indexOf("Mac")!=-1;
var InternetExplorer=navigator.userAgent.indexOf("MSIE")!=-1;
var	IE=((typeof document.all!="undefined") && (parseInt(navigator.appVersion)>=4))?1:0;
var Gecko=navigator.userAgent.indexOf("Gecko")!=-1;
var Safari=navigator.userAgent.indexOf("Safari")!=-1;
var Opera=navigator.userAgent.indexOf("Opera")!=-1;
var Konqueror=navigator.userAgent.indexOf("Konqueror")!=-1;

// controllo per oggetto null o undefined
function isNull(v) 		{ return (typeof(v)=="undefined"||v==null); }

// get element by ID (with browser check)
function getObj(objID) 	{ return (!document.getElementById?null:document.getElementById(objID));	}

// show and hide DIV
function alternateShow(divObjToShow,divObjToHide) {
	if (!isNull(divObjToHide)&&!isNull(divObjToHide.style)) {		// hide
		divObjToHide.style.display="none";
		if (Opera)		divObjToHide.style.visibility="hidden";		// aggiro baco background menu di Opera
	}
	if (!isNull(divObjToShow)&&!isNull(divObjToShow.style)) {		// show
		divObjToShow.style.display="block";
		if (Opera)		divObjToShow.style.visibility="visible";	// aggiro baco background menu di Opera
	}
}

// show or hide a object
function switchBoxObj(obj,show)	{
	if (isNull(obj))	return;
	obj.style.display=(show?"block":"none");
	if (Opera)	obj.style.visibility=(show?"visible":"hidden");		// aggiro baco background menu di Opera
}

// check a object visibility
function isVisible(obj)	{ 	return (!isNull(obj)&&obj.style.display!="hidden"&&obj.style.display!="none");	}

// toggle a object
function toggleObj(obj)	{	switchBoxObj(obj,!isVisible(obj)); }

// open a windows (custom parameters)
function popUp(url,x,y,menu,location,scrollbar,resize)		{

	// parametri popup
	var winParam="";
	if (menu)		winParam+=",toolbar=yes,menubar=yes";
	else			winParam+=",toolbar=no,menubar=no";
	if (location)	winParam+=",location=yes,status=yes";
	else			winParam+=",location=no,status=no";
	if (scrollbar)	winParam+=",scrollbars=yes";
	else			winParam+=",scrollbars=no";
	if (resize)		winParam+=",resizable=yes";
	else			winParam+=",resizable=no";
	
	// new windows
	var siteWindowVar=open(url,"popup"+x+"x"+y,"directories=no,width="+x+",height="+y+""+winParam);
	if (!isNull(siteWindowVar))		siteWindowVar.focus();
}


// update opener url
function updateOpener (url,newonerror,closeThisWin)	{
	if (!isNull(opener))	{
		opener.location=url;
		if (closeThisWin) opener.focus();
	} else if (newonerror) {
		window.open(url);
	}
	if (closeThisWin) self.close();
}