for (var i=1; i<5; i++) {
    eval("menu"+i+"_off=new Image()");
	eval("menu"+i+"_off.src='images/menu/menu"+i+"_off.jpg'");
	eval("menu"+i+"_on=new Image()");
	eval("menu"+i+"_on.src='images/menu/menu"+i+"_on.jpg'");
}

eval("home_off=new Image()");
eval("home_off.src='images/menu/home_off.jpg'");
eval("home_on=new Image()");
eval("home_on.src='images/menu/home_on.jpg'");