Summary

Form fields have been accessible via JavaScript since the earliest incarnations of the language. The primary goal in accessing form elements is to validate their contents before submission. However, we also saw in this chapter that usability improvements are possible using very small amounts of code. More complex examples, such as fully dynamic forms, are also possible, and with the DOM, forms can even be more dramatically modified. Programmers are encouraged to either write their own or obtain validation libraries to ensure the highest quality form data is submitted to their Web applications. However, JavaScript developers should always assume that their validation routines can be bypassed by a malicious user and perform checks on the server-side as well. The next chapter will examine another common use of JavaScript—image rollovers and screen animations.