Overlay Problem SO

HTML

<div class="wrapper">
				<div class="codeCont">
					<img src="http://jpowell43.mydevryportfolio.com/Port-2:14/images/psd-3T.jpg" alt="image" data="http://jpowell43.mydevryportfolio.com/Port-2:14/images/psd-3.jpg" />
					<img src="http://jpowell43.mydevryportfolio.com/Port-2:14/images/psd-2T.jpg" alt="image" data="http://jpowell43.mydevryportfolio.com/Port-2:14/images/psd-2.jpg" />
					<img src="http://jpowell43.mydevryportfolio.com/Port-2:14/images/psd-1T.jpg" alt="image" data="http://jpowell43.mydevryportfolio.com/Port-2:14/images/psd-1.jpg" />
				</div>
				<div class="overlay"><img src="" alt="Portfolio Image" /><span class="close">X</span></div>
			</div>
		</div>

CSS

.wrapper {
	width: 65%;
	height: 70%;
	margin: 0 auto;
	position: relative;
	top: 15%;
	left: 0;
	padding: 10px;
	overflow: scroll;
	background: rgba(255, 255, 255, 0.4);
}

.codeCont {
	max-width: 100%;
	margin-bottom: -10px;
	column-count: 3;
	-webkit-column-count: 3;
	-moz-column-count: 3;
	-o-column-count: 3;
	column-gap: 10px;
	-webkit-column-gap: 10px;
	-moz-column-gap: 10px;
	-o-column-gap: 10px;
}

.codeCont img {
	width: 100%;
	margin-bottom: 10px;
    cursor: pointer;
    display: block;
}

.overlay {
    width: 60%;
    left: 20%;
    top: 50%;
    position: fixed;
    z-index: 100;
    display: none;
    background-size: auto 100%;
    background-position: top center;
    background-repeat: no-repeat;
}

.overlay img {
	width: 100%;
}

.imgLong {
	width: 40%;
	left: 30%;
}

.close {
    width: 50px;
    height: 50px;
    position: absolute;
    right: 0;
    top: 0;
    background: rgba(255, 255, 255, 0.3);
    text-align: center;
    line-height: 50px;
    font-size: 3em;
    color: rgba(0, 0, 0, 0.6);
    text-shadow: 0 1px 0 rgba(255, 255, 255, 0.8);
    cursor: pointer;
}

JavaScript

function imgOverlay() {
		$('.codeCont img').on('click', function() {
			var imgData = $(this).attr('data');
			$('.overlay').fadeIn().find('img').attr('src', imgData);
			var iH = $('.overlay img').height()/2,
				safeInt = Math.floor(iH),
				imgH = "-" + safeInt + 'px';

			$('.overlay').css({
			    'margin-top' : imgH
			});
			
			if ($('.overlay img').attr('src') === 'images/vec-3.jpg') {
				$('.overlay').addClass('imgLong');
			}
			else {
				$('.overlay').removeClass('imgLong');
			}

			$('.close').on('click', function() {
			    $('.overlay').fadeOut();
			});
		});
	}

	imgOverlay();