bV = 0;
ver = parseInt(navigator.appVersion);
name = navigator.appName;
agent = navigator.userAgent;

if (name.indexOf("Netscape") != -1) {
	if (ver >= 3) { 
		bV = 3;
	} else { 
		bV = 0;
	}
} else { 
	if (agent.indexOf("MSIE") != -1) {
		if (ver >= 4) { 
			bV = 3;
		} else { 
			bV = 0;
		}
	} else {
		bV = 0;
	}
}

if (bV == 3) {
	i01 = new Image (); i01.src = "gfx/ms_hom_on.gif";
	i02 = new Image (); i02.src = "gfx/ms_ser_on.gif";
	i03 = new Image (); i03.src = "gfx/ms_por_on.gif";
	i04 = new Image (); i04.src = "gfx/ms_con_on.gif";
}

function navOver(name) {
	if(bV == 3){
		document[name].src = "gfx/ms_" + name + "_on.gif";
		return true;
	}
}

function navOut(name) {
	if(bV == 3){
		document[name].src = "gfx/ms_" + name + "_off.gif";
		return true;
	}
}

function navClick(name) {
	if(bV == 3){
		document[name].src = "gfx/ms_" + name + "_off.gif";
		return true;
	}
}