function swapImage(index) {
    for(i=0; i < menuOptions.length; i++) {
        if(menuOptions[i] != index) {
                document.getElementById("menu"+menuOptions[i]).style.visibility = "hidden";
                document.getElementById("topMenuOff"+menuOptions[i]).style.visibility = "visible";
                document.getElementById("topMenuOn"+menuOptions[i]).style.visibility = "hidden";
        } else {
                document.getElementById("menu"+index).style.visibility = "visible";
                document.getElementById("topMenuOff"+menuOptions[i]).style.visibility = "hidden";
                document.getElementById("topMenuOn"+menuOptions[i]).style.visibility = "visible";
        }
    }
}
var menuOn =new Array();
var menuOff = new Array();
var menuOptions = new Array();

menuOptions.push("Home");    
menuOptions.push("Visit");
menuOptions.push("Exhibitions");
menuOptions.push("The Collection");       
menuOptions.push("Membership");    
menuOptions.push("Education");    
menuOptions.push("About");