Centre images in Nivo Slider

[PhantomX]

I have a Nivo Slider on my website, please see code below:\[code\]<!-- SLIDER START --> <div id="wrapper"> <div class="slider-wrapper theme-default"> <div id="slider" class="nivoSlider"> <img src="http://stackoverflow.com/questions/15656247/slider/images/image.jpg" /> </div><!-- SLIDER END -->/*===================*//*=== Main Styles ===*//*===================*/.theme-default #slider { margin: 0 auto 0 auto; width: 100%; /* Make sure your images are the same size */ height: 400px; /* Make sure your images are the same size */}.theme-pascal.slider-wrapper,.theme-orman.slider-wrapper { margin-top:35px;}\[/code\]As you can see the width of the actual slider is 100% so it will always fit the width of the window.some of the images are not going to be the same width as the users window as it is 100% but i cannot get the images in the slider to center for some reason.i have done margin: 0 auto 0 auto; to try and make it centre but still nothingany ideas on this?