var size = $(document).width() * 0.2;
$.each("/Image/BigImage/backGround.png,/Image/BigImage/test.jpg".split(','), function (i, src) {
var img = new Image();
img.src = src;
img.onload = function () {
var rate = img.width / img.height;
var $div = $('<div></div>').height(size).append($(img).css(rate > 1 ?
{ 'height': size, 'width': rate * size, 'margin-top': -5, 'margin-left': (1 - rate) * size / 2 } :
{ 'height': size / rate, 'width': size, 'margin-top': (1 - 1 / rate) * size / 2 - 8, 'margin-left': -2 }
));
$('.jupload1-list').append($div);
}
})