Webmaster Forum / HTML, CSS, Scripts / JavaScript / January 2005

 No.

   " In fact, all user-defined properties (which includes all
     variables) are erased whenever a web page is unloaded. The
     scripts in a freshly loaded document start with no variables
     defined, and no properties in their Window object, except
     for the standard properties defined by the system. What this
     means is that the lifetime of scripts and of the variables
     they define is the same as the lifetime of the document that
     contains the script. This is potentially much shorter than
     the lifetime of the window or frame that displays the
     document that contains the script."


<URL:http://www.web-developer-india.com/web/jscript/ch11_06.html#ch11-SECT1-AUTOID.6>

Javascript uses automatic garbage collection and should free memory when
pages unload. There is, however, a running problem with IE browsers. If
_circular_ references are constructed between ECMAScript native objects
and DOM/COM objects then IE's garbage collection cannot recognise when
it is appropriate to free those objects. This can result in memory
leaks, but the references have to be circular before this is an issue.
One of the strategies for dealing with this problem is to break circular
references onunlod. Others include never creating such references or
breaking such references at the end of functions that create them.
Javascript closures are the most common source of problematic circular
references between javascript objects and DOM/COM objects (the c.l.js
FAQ includes an article on closures with some coverage of the memory
leak problem).

Richard.