[Javascript] Change Extensions

[Travis.Falls at thehartford.com (Falls, Travis D (HTSC, CASD))]

I am trying to write a javascript method that will use regular expressions
to figure out the file extension of a file name (String) and change it.
Basically I need to find ".*" and replace it with ".working"  I don't know
how to write this regular expression though.  Can someone explain how to do
this? (not just send over the regular expression I want to learn how to do
this).  Thanks.  

Travis D. Falls | Consultant   RAFT.Net   IT | 860.547.4070 |
travis.falls@xxxxxxxxxxxxxxx


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