/* use opacity */
.glayer {
    position: fixed!important;
    position: absolute;
    top:0;
    left:0;
    width:100%;
    height:100%;
    z-index:100;
    background-color:#1F1F1F;
    -moz-opacity: 0.8;
    opacity:.80;
    filter: alpha(opacity=80);
}

/* use png */
.glayer_img {
    position: fixed!important;
    position: absolute;
    top:0;
    left:0;
    width:100%;
    height:100%;
    z-index:100;
    background-image: url(glayer.png);
}
* html .glayer_img {
    background-image: none;
    filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src="glayer.png", sizingMethod="scale");
}