How do I highlight a droppable area on hover using jquery ui draggable

Check out http://jqueryui.com/demos/droppable/#visual-feedback.

Ex:

$( "#draggable" ).draggable();
$( "#droppable" ).droppable({
    hoverClass: "ui-state-active",
    drop: function( event, ui ) {
        $( this )
            .addClass( "ui-state-highlight" )
            .find( "p" )
                .html( "Dropped!" );
    }
});
$( "#draggable2" ).draggable();
$( "#droppable2" ).droppable({
    accept: "#draggable2",
    activeClass: "ui-state-hover",
    drop: function( event, ui ) {
        $( this )
            .addClass( "ui-state-highlight" )
            .find( "p" )
                .html( "Dropped!" );
    }
});