The code looks right to me...
Do you have access to the server? If so, check the permissions on the database. Open Windows Explorer, go to the database file, right-click it, select Properties and then click on the permissions tab. In the top box, you should see a user named IUSR_... Click it and then look at the checkboxes at the bottom. Make sure that the Write box is checked. If you don't see an IUSR_ account, the server is probably using the Everyone group to access the file, so you'll need to add IUSR_ to the list. Click Add then select IUSR from the list. Make sure that you give IUSR_ read and write access (should be the same as Everyone, plus the Write checkbox).
Hope this helps...