HTML | onbeforeunload Event Attribute
The onbeforeunload event run when the document is about to be unloaded. This event is used to allow to display a message in a dialog box to inform the user to he/she wants to stay or leave the current page.
Supported Tags
- <body>
Syntax:
<element onbeforeunload = "script">
Attribute Value: This attribute contains single value script and it runs when onbeforeunload event called. This event attribute is supported by <body> tag.
Example:
html
<!DOCTYPE html> < html > < head > < title >onbeforeunload attribute</ title > < style > body { text-align:center; } h1 { color:green; } a { text-decoration:none; font-weight:bold; } </ style > </ head > < body onbeforeunload = "return myFunction()" > < h1 >GeeksforGeeks</ h1 > < h2 >onbeforeunload attribute</ h2 > < script > function myFunction() { return "This document is ready to load"; } </ script > </ body > </ html > |
Output:
Supported Browsers: The browser supported by onbeforeunload attribute are listed below:
- Google Chrome
- Internet Explorer
- Firefox
- Safari
- Opera 15.0 and above