JavaScript and Ajax for the Web: Visual QuickStart Guide, Seventh Edition

Handling Window Events

Window events occur when the user does something affecting an entire browser window. The most common window event is simply loading the window by opening a particular Web page. You can also have events that trigger event handlers when windows are closed, moved, or even sent to the background.

When working with event handlers, you’ll often find it useful to connect an event handler to an object using dot syntax, like so:

window.onfocus
window.onload
document.onmousedown

Note that when you use the event handler as part of an object like this, the event handler is written all in lowercase. Also, keep your event handlers in external scripts, rather than placing them inside the HTML tag—this approach is more standards compliant, ...