#slideshow { 
    background:transparent;
    position: fixed;
    width: 100%;
    height: 100%;
    left:0;
    top:0;
    z-index: -1;
}

#slideshow > div { 
    position: absolute;
    z-index: -1;
    
}

img.bg_slide{
    width: 100%;
    height: 100%;
    top:0;
    bottom:0;
    left:0;
    right:0;
}