Karim Kiswarday wrote:I think it's superfluous but maybe it's not.
No "maybe" about it. Why would I have put it there if it's superfluous?
The object returned from any call to the $ function is a jQuery wrapped set. It is not a reference to the selected elements (remember, many elements could have been selected). Just because only one element is selected doesn't change the fact that the object is a set, not a single element.
You could also use .get(0) to obtain the reference.
(You may want to go back and reread chapter 2 if any of this is a surprise to you.)
You are thinking DOM objects and JQuery objects are interchangeable, they are not. When you use  you get the DOM element which has onmouseover. If you do it with the jQuery object you get an error. Check the console.
Look at that link I sent you find what you would use for onmouseover and review the portion of the book that talks about bind.