JavaScript® Bible, Sixth Edition

Chapter 22. Button Objects

IN THIS CHAPTER

• Triggering action from a user's click of a button

• Assigning hidden values to radio and checkbox buttons

• Distinguishing between radio button families and their individual buttons

This chapter is devoted to those lovable buttons that invite users to initiate action and make choices with a single click of the mouse button. In this category fall the standard system-looking buttons with labels on them, as well as radio buttons and checkboxes. For such workhorses of the HTML form, these objects have a limited vocabulary of object-specific properties, methods, and event handlers.

I group together the button, submit, and reset objects for an important reason: They look alike yet they are intended for very different purposes. Knowing when to use which button is important—especially when to differentiate between the button and submit objects. Many a newcomer gets the two confused and winds up with scripting error headaches. That confusion won't happen to you by the time you finish this chapter.

The button Element Object, and the Button, Submit, and Reset Input Objects

For HTML element properties, methods, and event handlers, see Chapter 15.

Properties	Methods	Event Handlers
form	click()	onclick
name		onmousedown
type		onmouseup
value

Syntax

Accessing button object properties or methods:

(All)      [window.]document.formName.buttonName.property | method([parameters])
(All)      [window.]document.formName.elements[index].property | method([parameters]) (All) [window.]document.forms[ ...