jQuery crop tool with large images

I have a <img> tag which shows images. If I load large images I need to re-size it using th开发者_开发技巧e following CSS code

.resize-large-images
{
    min-width:100px;
    max-width:100%;
    width:auto !important;
    height: auto !important;
}

The CSS works fine. But when I use it with the jcrop it again loads in the actual size. What should I do to overcome this issue ? Edit jcrop files ? Or is there any alternatives ?

$(function() {
       $('#cropbox').Jcrop({ boxWidth: 450, boxHeight: 400 });
 })