Auto-resize a same-domain iframe to the height of it's content

jquery.iFrameAutoHeight.js

        (function($) {
            $.fn.extend({
                iFrameAutoHeight: function() {
                    return this.each(function() {
                        var obj = $(this);
                        obj.height(0); //avoid flash at full height
                        if (obj.contents().find('body').height() > 0) { // already loaded - from cache (ie only)
                            resize(obj);
                        } else {
                            obj.load(function() {
                                resize(obj);
                            })
                        }
                    });

                    function resize(obj) {
                        obj.height(obj.contents().find('body').height());
                    }
                }
            });
        })(jQuery);

This presumes that the iframe content is static, so the resize event isn't used