onload event is used to trigger an action once a
web page has completely loaded all content and, importantly, all of the
external resources that the page calls in (including images, script files,
CSS files, and so on).
It may also be used in the context of
framesets to indicate that the child
frame elements have finished
is used as an inline attribute, it’s most frequently applied to the
body element, as shown below:
This attribute has no fixed value.
It’s up to the author to decide on the scripting that’s included here, be
that a call to one or more defined functions, or a simple
Every browser listed supports this attribute. However, inline event handlers such as this should be avoided. In the same way that inline CSS styles are frowned upon but externally defined CSS styles are considered good practice, inline event handlers should be stripped out and replaced with events attached unobtrusively through the DOM.