function roll_over(img_name, img_src)
{
    var ele = document.getElementById(img_name);
    ele.src = img_src;

}
/*
function showSecNav() {
    hideSecNavs();
    document.getElementById('secNav').style.visibility = 'visible';
}


function hideSecNavs() {
    document.getElementById('secNav').style.visibility = 'hidden';

}
*/
function showSecNav() {
    hideSecNavs();
    document.getElementById('secNav').style.visibility = 'visible';
}



function hideSecNavs() {
    if (document.getElementById('secNav'))
        document.getElementById('secNav').style.visibility = 'hidden';
}