css - How to create a drop shadow only on one side of an element?

Question

Is there a way to drop the shadow only on the bottom?. I have a menu with 2 images next to each other. I don't want a right shadow because it overlaps the right image. I don't like to use images for this so is there a way to drop it only on the bottom like:

box-shadow-bottom: 10px #FFF; or similar?

-moz-box-shadow: 0px 3px 3px #000;
-webkit-box-shadow: 0px 3px 3px #000;
box-shadow-bottom: 5px #000;
/* For IE 8 */
-ms-filter: "progid:DXImageTransform.Microsoft.Shadow(Strength=4, Direction=180, Color='#000000')";
/* For IE 5.5 - 7 */
filter: progid:DXImageTransform.Microsoft.Shadow(Strength=4, Direction=180, Color='#000000');

Answer 1

UPDATE 4

Same as update 3 but with modern css (=fewer rules) so that no special positioning on the pseudo element is required.

#box {
    background-color: #3D6AA2;
    width: 160px;
    height: 90px;
    position: absolute;
    top: calc(10% - 10px);
    left: calc(50% - 80px);
}

.box-shadow:after {
    content:"";
    position:absolute;
    width:100%;
    bottom:1px;
    z-index:-1;
    transform:scale(.9);
    box-shadow: 0px 0px 8px 2px #000000;
}

<div id="box" class="box-shadow"></div>