aspnetdb.mdf access error

[Keith]

Using the vs built-in web server, when I run my application in debug mode
one time and try to run in debug mode a second time, I get the following
error message:

"The process cannot access the file "aspnetdb.mdf" because it is being used
by another process."

I have to close VS and restart it before I can run my application in debug
mode. Any ideas about the cause?

Thanks,

Keith