IN THIS CHAPTER
What client-side scripts do
What happens when a document loads
How the browser creates objects
How scripts refer to objects
What distinguishes one object from another
If you have authored web pages with HTML, you are familiar with how HTML tags influence the way content is rendered on a page when viewed in the browser. As the page loads, the browser recognizes angle-bracketed tags as formatting instructions. Instructions are read from the top of the document downward, and elements defined in the HTML document appear on-screen in the same order in which they appear in the document's source code. As an author, you do a little work one time and up front—adding the tags to text content—and the browser does a lot more work every time a visitor loads the page into a browser.
Assume for a moment that one of the elements ...