(function($){
    $.extend({
        "autoImage" : function(options){   
            options = options || {};
            options = $.extend({
                "parent"         : null,
                "loadClassId"    : "loading",
                "src"            : "",
				"url"            : "",
				"alt"            : ""
            },options);
            var parent = options.parent;
            if(parent == null || parent.length == 0) return;
            parent.addClass(options.loadClassId);
			var url = (options.url) ? options.url : options.src;
            if(options.src) parent.html("<a href='"+url+"' title='"+options.alt+"' target='_blank'><img alt='"+options.alt+"' /></a>");
            var image   = parent.find("img");
            var src     = (options.src) ? options.src : image.attr("src");
            var img     = new Image();
            img.src     = src;   
   
            if(img.complete){
                image.attr("src",img.src);
                parent.removeClass(options.loadClassId);
                imgAuto();
                return;
            }
   
            image.attr("src","");
            image.hide();
            $(img).load(function(){
                imgAuto();
                image.attr("src",this.src);
                image.fadeIn("normal",function(){
                    parent.removeClass(options.loadClassId);   
                });
            });   
   
            function imgAuto(){    
                var width   = img.width;
                var height  = img.height;
                var pwidth  = parent.width();
                var pheight = parent.height();
                if(width>0 && height>0){
                    var rate = (pwidth/width < pheight/height) ? pwidth/width : pheight/height;
                    if(rate <= 1){
                        width  *=  rate;
                        height *=  rate;
                    }
                    var left = (pwidth - width) * 0.5;
                    var top  = (pheight - height) * 0.5;
                    image.css({
                        "margin-left" : left + "px",
                        "margin-top"  : top + "px",
                        "width"       : width + "px",
                        "height"      : height + "px"
                    });
                }
            }
   
        }
    });
    $.fn.extend({
        "autoImage" : function(src,url,alt,loadClassId){
            return this.each(function(){       
                $.autoImage({
                    "parent"      : $(this),
                    "src"         : src,
					"url"         : url,
					"alt"         : alt,
                    "loadClassId" : loadClassId
                });
            });
        }
    });
})(jQuery);