#middleCol {
    position: relative;
    padding: 0;
    margin: 0;
    height: 100%;
    min-height: 100%;
}
#middleCol::after {
    content:'';
    display: block;
    height: 108px;
}
#bannerFour {
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 108px;
}