var prefix = '/';
if (/https:\/\//.test(location.href)) {
    prefix = 'https://www.e-tutor.com/';
}

if (document.images) {
    img1 = new Image();
    img1.src = prefix + "enroll_ovr.gif";
    img2 = new Image();
    img2.src = prefix + "tour_ovr.gif";
    img3 = new Image();
    img3.src = prefix + "subscribe_ovr.gif";
}
function ovr( buttonname )
{
    if (document.images) {
      document.getElementById( buttonname ).src = prefix + buttonname + "_ovr.gif";
    }
}
function out ( buttonname )
{
    if (document.images) {
      document.getElementById( buttonname ).src = prefix + buttonname + ".gif";
    }
}