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JavaScript: The Definitive Guide, Fourth Edition
book

JavaScript: The Definitive Guide, Fourth Edition

by David Flanagan
November 2001
Intermediate to advanced content levelIntermediate to advanced
936 pages
68h 43m
English
O'Reilly Media, Inc.
Content preview from JavaScript: The Definitive Guide, Fourth Edition

Name

Input.onfocus — the handler invoked when a form element gains focus

Availability

JavaScript 1.0

Synopsis

<input type="type"onfocus="handler"> input.onfocus

Description

The onfocus property of an Input object specifies an event handler function that is invoked when the user transfers keyboard focus to that input element. Calling focus( ) to set focus to an element does not invoke onfocus for that object.

The initial value of this property is a function that contains the semicolon-separated JavaScript statements specified by the onfocus attribute of the HTML tag that defined the object. When an event handler function is defined by an HTML attribute, it is executed in the scope of element rather than in the scope of the containing window.

In the Netscape 4 event model, the onfocus handler function is passed an Event object as an argument. In the IE event model, no argument is passed, but the applicable Event object is available as the event property of the Window object that contains the element.

The onfocus event handler is available for all form elements except the Hidden element. In Netscape on Unix platforms, however, it is invoked only for the text-entry elements: Text, Textarea, Password, and FileUpload. Note that in JavaScript 1.1, the Window object also defines an onfocus event handler.

See Also

Window.onfocus; Chapter 19; Event, EventListener, and EventTarget in the DOM reference section

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Publisher Resources

ISBN: 0596000480Supplemental ContentCatalog PageErrata