Handle with Care
Of course, Ajax is not for everyone (particularly those dessert topping fans!). Because Ajax technology can dynamically alter a web page that has already been downloaded, it may interfere with certain functions near and dear to many users, such as creating bookmarks for browser views. For example, in the absence of fancy scripting solutions, the dynamic changes you make with DOM in an existing web page cannot be linked to with a URL that you can send to your friends or save for later. (Both "Fix the Browser Back Button in Ajax Applications" [Hack #68] and "Handle Bookmarks and Back Buttons with RSH" [Hack #69] should help shed light on these issues and provide some hackable solutions.)
A number of the cool Ajax tips described in this book alter the behavior of many familiar web widgets, such as select lists, textareas, text fields, and radio buttons that submit their own data and talk to servers behind the scenes. However, bear in mind that Ajax-powered widgets should be first and foremost usable, and always avoid confusing and irritating web users.