لطفا منتظر باشید ...
•
Table of Contents
•
Index
•
Reviews
•
Examples
•
Reader Reviews
•
Errata
JavaScript: The Definitive Guide, 4th Edition
By
David Flanagan
Publisher
: O'Reilly
Pub Date
: November 2001
ISBN
: 0-596-00048-0
Pages
: 936
Slots
: 1
This fourth edition of the definitive reference to
JavaScript, a scripting language that can be embedded
directly in web pages, covers the latest version of the
language, JavaScript 1.5, as supported by Netscape 6 and
Internet Explorer 6. The book also provides complete
coverage of the W3C DOM standard (Level 1 and Level 2),
while retaining material on the legacy Level 0 DOM for
backward compatibility.
Availability
JavaScript 1.0
Synopsis
<body onunload="handler" ... ><frameset onunload="handler" ... >
window.onunload
Description
The onunload property of a Window specifies an
event handler function that is invoked when the browser
"unloads" a document or frameset in preparation for
loading a new one.
The
initial value of this property is a function that contains the
semicolon-separated JavaScript statements specified by the
onunload attribute of the
<body> or
<frameset> tags. The
onunload event handler provides the opportunity to
perform any necessary cleanup of the browser state before a new
document is loaded.
When the browser leaves a site using frames, the
onunload handler of the frameset is invoked before
the onunload handler for each of the frames. This
is the reverse of the order in which the onload
event handler is invoked.
The onunload( ) handler is invoked when the user
has instructed the browser to leave the current page and move
somewhere else. Therefore, it is usually inappropriate to delay the
loading of the desired new page by popping up dialog boxes (with
Window.confirm( ) or Window.prompt(
), for example) from an onunload event
handler.
See Also
Window.onload; Chapter 19; Event, EventListener,
and EventTarget in the DOM reference section
