[Javascript] live counter help!!!

[salim at vodatel.com (S.F. Alim)]

Hi list,
 
Im just a beginner in programming world and javascript is like a black hole for me, so I will simple ask and wait for list to answer?
 
How do you increase to a counter without refreshing the whole page. For example if you check site www.gmail.com <http://www.gmail.com/>  under ?Don't throw anything away.? Heading there is counter which is increasing, 
?And other example is www.neopets.com <http://www.neopets.com/>  where time (seconds) is changing without refreshing the whole page.
 
Any link or hint or code will be welcome ( even comments ) ;)
Thanks in advance.
salim
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.LaTech.edu/pipermail/javascript/attachments/20050508/496d9da2/attachment.html