This is asked all the time. Do a search.
Keep in mind though, that your user can easily go to the database window and
just run the report form there. They could also look at the code behind
your form and read your password. Or, they could open the actual table and
read the data there. In most cases, they could create their own report to
get the results, or do so in a query.
In short, home-grown security and quick passwords built in code are rarely
very secure. The proper way to secure your database is to implement
user-level security and force all users to log in with a userid and
password. Then, you can define to what objects they have access, and what
kind of access they have.
Read the previous posts on the topic (often called "password protect a
form") for more information, or post back here.
Keep in mind, User-level security is very detailed to implement. It is not
difficult, but you must follow all the steps in order.