<p>There have been some questions about whether or not JavaScript is an object-oriented language. Even a statement, "just because a language has objects doesn't make it OO."</p>

<p>Is JavaScript an object-oriented language?</p>

The short answer is Yes. For more information:
From
Wikipedia
:
JavaScript is heavily object-based.
  Objects are associative arrays,
  augmented with prototypes (see below).
  Object property names are associative
  array keys: obj.x = 10 and obj["x"] =
  10 are equivalent, the dot notation
  being merely syntactic sugar.
  Properties and their values can be
  added, changed, or deleted at
  run-time. The properties of an object
  can also be enumerated via a for...in
  loop.
Also, see
this series of articles
about OOP with Javascript.