How to make an option on which database to connect using VB

Good day! I'm currently working on a project and I'm trying to make a Log-In and Registration System for a certain office.
To start with, a Registration form will show up with few fields to be filled up. It will also require a picture of you and your thumb mark. You can use these credentials the next time you want to log-in. By the way, I'm using Microsoft SQL Server 2008. Here's my problem, prior to the Registration form, I want to make a form containing a Listbox in which I can choose on which database to connect given that I have multiple databases in my server. I really don't have an idea on how to execute this. Any help will be appreciated. Thanks.