onbeforeunload Event

Fires prior to a page being unloaded.

Syntax

Inline HTML <ELEMENT onbeforeunload = "handler" ... > All platforms

Event property object.onbeforeunload = handler JScript (compatible with ECMA 262 language specification) only

Named script <SCRIPT FOR = object EVENT = onbeforeunload> Internet Explorer only

Inline HTML	<ELEMENT onbeforeunload = "handler" ... >	All platforms
Event property	object.onbeforeunload = handler	JScript (compatible with ECMA 262 language specification) only
Named script	<SCRIPT FOR = object EVENT = onbeforeunload>	Internet Explorer only

Remarks

Bubbles No

Cancels No

To invoke

Close the current browser window.
Navigate to another location by entering a new address or selecting a Favorite.
Click the Back, Forward, Refresh, or Home button.
Click on an anchor that refers the browser to another Web page.
Invoke the anchor click method.
Invoke the document write method.
Invoke the document open method.
Invoke the document close method.
Invoke the window close method.
Invoke the window open method, providing the possible value _self for the window name.
Invoke the window navigate or NavigateAndFind method.
Invoke the location replace method.
Invoke the location reload method.
Specify a new value for the location href property.
Submit a FORM to the address specified in the ACTION attribute via the INPUT_submit control, or invoke the form submit method.

Default action Signals that the page is about to be unloaded.

When a string is returned to this event, a dialog box displays that gives the user the option of staying on the page.

Bubbles	No
Cancels	No
To invoke	Close the current browser window. Navigate to another location by entering a new address or selecting a Favorite. Click the Back, Forward, Refresh, or Home button. Click on an anchor that refers the browser to another Web page. Invoke the anchor click method. Invoke the document write method. Invoke the document open method. Invoke the document close method. Invoke the window close method. Invoke the window open method, providing the possible value _self for the window name. Invoke the window navigate or NavigateAndFind method. Invoke the location replace method. Invoke the location reload method. Specify a new value for the location href property. Submit a FORM to the address specified in the ACTION attribute via the INPUT_submit control, or invoke the form submit method.
Default action	Signals that the page is about to be unloaded.

Event Object Properties

Although event handlers in the DHTML Object Model do not receive parameters directly, the handler can query the event object for data.
Event Object Properties

altKey Retrieves the current state of the ALT key.

clientX Retrieves the x-coordinate of the mouse cursor relative to the client area of the window, excluding window decorations or scroll bars.

clientY Retrieves the y-coordinate of the mouse cursor relative to the client area of the window, excluding window decorations or scroll bars.

ctrlKey Retrieves the state of the CTRL key.

returnValue Sets or retrieves the return value from the event.

shiftKey Retrieves the state of the SHIFT key.

type Retrieves the event name from the event object.

altKey	Retrieves the current state of the ALT key.
clientX	Retrieves the x-coordinate of the mouse cursor relative to the client area of the window, excluding window decorations or scroll bars.
clientY	Retrieves the y-coordinate of the mouse cursor relative to the client area of the window, excluding window decorations or scroll bars.
ctrlKey	Retrieves the state of the CTRL key.
returnValue	Sets or retrieves the return value from the event.
shiftKey	Retrieves the state of the SHIFT key.
type	Retrieves the event name from the event object.

Example

This example uses the onbeforeunload event to prompt the user to remain on the page.

Sample Code

<HTML>
<HEAD>
<SCRIPT>
function closeIt()
  {
    event.returnValue = "Any string value here will force a dialog 
                         box to appear before closing the window.";
  }
</SCRIPT>
</HEAD>
<BODY onbeforeunload="closeIt()">
<P>Navigate to another page to fire the before unload event.
</BODY>
</HTML>

Applies To

[ Object Name ]

Platform Version

Win16:

Win32:

Mac:

Unix:

WinCE:

Version data is listed when the mouse hovers over a link, or the link has focus.

FRAMESET, window