Cadena de Conexion VB.net y SQL Server

Imports System.Data.SqlClient
Public Class Config
    Protected cnn As SqlConnection

    '---------------------- METODO QUE ABRE LA CONEXION A LA BASE DE DATOS ------------------------------
    Protected Function conectado()
        Try
            Dim cadena As String
            'cadena = "data source =tcp:SERVIDOR\SERVERAVIKAR,49500; DataBase=SisAvikarDemo; User ID=avikar; Password=root123"
            cadena = "data source =localhost; initial catalog=SisAvikarDemo; User ID=Naoemi; Password=Pantagarcia"
            'cadena = "Server=tcp:BITPANG98\SERVER,49500; DataBase=SisAvikarDemo; User ID=bitpang98; Password=bitpang1998"

            cnn = New SqlConnection(cadena)
            cnn.Open()
            Return True

        Catch ex As Exception
            Return MsgBox(ex.Message, MsgBoxStyle.Critical)
        End Try
    End Function

    '--------------------- METODO QUE PERMITE CERRAR LA CONEXION A LA BASE DE DATOS -----------------------
    Protected Function desconectado()
        Try
            If cnn.State = ConnectionState.Open Then
                cnn.Close()
                Return True
            Else
                Return False
            End If
        Catch ex As Exception
            Return MsgBox(ex.Message, MsgBoxStyle.Critical)
        End Try
    End Function
End Class