function overImg(i){
    var img = document.getElementsById(i);
    var overImage = "images/mm_" + i + "_selected.gif";
    img.src = overImage;
}

function offImg(i){
    var img = document.getElementsById(i);
    var offImage = "images/mm_" + i + "_deselected.gif";
    
    img.src = offImage;
}