IMHO, there is not much difference in case of web application if you look at it from the angle of responsibility assignment. However, keep the clarity in the layer. Keep anything purely for the presentation purpose in the presentation layer, like the control and code specific to the web controls. Just keep your entities in the business layer and all features (like add, edit, delete) etc in the business layer. However rendering them onto the browser to be handled in the presentation layer. For .Net, the ASP.NET MVC pattern is very good in terms of keeping the layers separated. Look into the MVC pattern.
