How to read data using SQLDATAREADER using VB.NET

Imports System.Data.SqlClient

Dim sqlConnection As SqlConnection
Dim sqlCommand As SqlCommand
Dim dr As New SqlDataReader

connstring = "Data Source=localhost;Initial Catalog=Test;User id=username;password=password;"
sqlcon.ConnectionString = connstring
sqlcon.Open()

sqlCommand = New SqlCommand("Select * from tablename", sqlConnection)

dr = sqlcommand.ExecuteReader()

While dr.read
Msgbox dr("FirstField")
Msgbox dr("SecondField")
End While

dr.close
sqlconnection.close