if (document.images) 
{
    nav = new Array();
    nav[01] = new Image();
    nav[01].src = "App_Themes/six-its/images/info.gif";
    nav[02] = new Image();
    nav[02].src = "App_Themes/six-its/images/info_ovr.gif";
}

function change_nav(from,to)
{
    if(document.images) {
        document.images[from].src = nav[to].src;
    }
}