The brackets should have contain the name of the place, and yes that was “part” of the problem.
It also depends if you are using the “Classic” Google Map or the “New” version that is being developed. The Chrome browser has been encouraging users to switch to the new version to test it.
The new code supplied works in both. It changes the url to http://maps.google.com/?q=Sevenoaks&ll=51.278826,0.183874