This is a modification of the TSQL script from Steve Jones -
www.dkranch.net I use since several years.
This new version kills only programs with "Navision" in their name and warn users with a "net send" message.
This archive contain a SQL Server job which run the script once per minute and kills idle sessions for more than 30 minutes.
http://www.mibuso.com/dlinfo.asp?FileID=367