html, body {
    height: 100%;
}

#wrap {
    min-height: 100%;
}

#main_contain {
    overflow:auto;
    padding-bottom:150px;
}
.footer {
    position: relative;
    margin-top: -150px;
    padding: 10px;
    clear:top;
    height: 150px;
    background-color: #f5f5f5;
}