bash or operator

Hi,

I have the following code:

viewserver=`hostname`
echo "$viewserver"
echo "Checking we are running on a viewserver... "
if [ "${viewserver}" != "viewserver1" -o "${viewserver}" != "viewserver2" ]; then
echo "ERROR: Not running on \"viewserver1\" or \"viewserver2\"!"
exit 1
fi

but it doesn't work with the "or" operator. Tried several different formats there but still end up with:

% ./bash_test
viewserver1
Checking we are running on a viewserver...
ERROR: Not running on "viewserver1" or "viewserver2"!

Any ideas what I'm doing wrong here?

Thanks
Tom

.