Detecting upgrades from a web browser

[Ted Baldwin]

I am asking this question for a friend currently creating software in the 
health care industry for processing insurance claims.  I figured this
type of question could be pertinent to libraries & info centers, so I hope
I explain this question clearly. He is interested in pushing / providing  
software and software upgrades to end-users through a web browser.  For
the upgrades, he would like built-in functionality that would
automatically detect and prompt the user if there is an upgrade to the
software available.  This would occurwhen the user logs onto their
website.  I thought this could be performed using some sort of script to 
detect the last file downloaded by the user, but there could be other
methods more effective.  He didn't know how other people were doing it,
and wanted some ideas.  If there is any interest, I can summarize for the
list.  TIA for your help and let me know if you need any clarification.  

- Ted

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Ted Baldwin
University Libraries
University of Cincinnati
513-530-4046 / 513-556-1503
513-530-4401 FAX
ted.baldwin at uc.edu