how to read from a database of access is given in the links
here[
^] and the link in answer 1.
The point I would like to point out is that if you are storing your passwords on the access database as they are (in other words, say a password is "123abc", and you put this into the database as "123abc"), anybody who could use the database will see the usernames and passwords.
A more convenient approach would be storing MD5 or SHA2 values of the passwords. In the check, you compare the hashed value of the password entered with the hashed value stored. In this manner, even if someone sees the database, he will not be able to get the pass codes.
Of course one down side is, you will not be able to recover lost passwords; they should be reset since they cannot be de-hashed.