DraggableTarget does not work

[bhupat parmar]

hi
this code does not compile  gives followinf error

The type WebMarkupContainer is not generic; it cannot be parameterized
with arguments <T>      wicket-quickstart/src/wicket/quickstart Index.java      
line
0       1189580276390   11921


 DraggableTarget cart = new DraggableTarget("cart",
DragDropExamplePageContribution.class);

        //kindof confusing parameters
        //product is the wicketId
        //product_123 is the HTML image id
        //tee_shirt.gif is the image to load
        DraggableImage image = new DraggableImage("product",
"product_123", "tee_shirt.gif");

        //need to configure cart to accept the draggable image
        cart.accepts(image);

        add(image);
        add(cart);

Can some body help me??

thanks