David,

I'm not sure if this works with your database but I use it on MS SQL. To validate the value entered by a user I simply pass the value in a select statement and check it a record was returned.

Regarding your connection problem. I'm not really sure about the connection string to your database. What you can do is create a connection using visual basic visual object like the connection object. Test the connection and if it works just copy the connection string in the object.

Hope that works.

Martin