There are some significant problems with that technique though. First, you cannot have multiple scripts automatically assigning the onload event, because one will replace the other. Second, the onload event loads very late, compared with putting the script at the bottom.
When the page is loading, it runs the scripts at the bottom of the body as soon as it gets to them. After they have finished loading the ondomready event fires on some web browsers, after which the web browser continues to load images and other content for the page. Only after the page has fully completed loading does the onload event fire.
[Putting your scripts at the bottom of the web page is one of the best practice for [url="http://developer.yahoo.com/performance/rules.html"]speeding up your web site](http://developer.yahoo.com/performance/rules.html#js_bottom).