Belajar Visual Basic Yuk ...

If Not conn Is Nothing Then conn.Close()

Dim connStr As String
connStr = String.Format("server={0};user id={1}; password={2}; database=mysql; pooling=false", _
server.Text, userid.Text, password.Text )

Try
conn = New MySqlConnection(connStr)
conn.Open()

GetDatabases()
Catch ex As MySqlException
MessageBox.Show("Error connecting to the server: " + ex.Message)
End Try