var supportOk = (parseInt(navigator.appVersion)>=4);

if (supportOk) {
	var imgDir = "img/";
	
	//rollovers 4 da header
	
	h0on = new Image();
	h0on.src = imgDir + "hhome_on.gif";
	h0off = new Image();
	h0off.src = imgDir + "hhome.gif";
	
	h1on = new Image();
	h1on.src = imgDir + "hcontatti_on.gif";
	h1off = new Image();
	h1off.src = imgDir + "hcontatti.gif";
		
	function turnOn(img) {
		eval("document."+img).src = eval(img+"on").src;
	}
	
	 function turnOff(img) {
		eval("document."+img).src = eval(img+"off").src;
	}
}