How To Test For Row

I am trying to test to see if my code is returning rows.  If it's not I want to display an error saying "Nothing Found"  Please review and give me your thoughts on the best way to accomplish this.

  1 Protected Sub btnLogin_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnLogin.Click
2 Dim SubEmail As String
3 Dim SubPassword As String
4 SubEmail = txtNewsEmails.Text
5 SubPassword = txtNewsPassword.Text
6 Session("NewsEmail") = SubEmail
7 Session("NewsPassword") = SubPassword
8 Dim sID As Integer
9
10 Dim cs As String = ConfigurationManager.ConnectionStrings("csTiPs3").ConnectionString
11 Dim cn As SqlClient.SqlConnection = New SqlClient.SqlConnection(cs)
12 cn.Open()
13 Dim selectString As String = "Select SubscriberID from NewsletterSubscribers WHERE SubscriberEmail = '" + SubEmail + "' AND SubscriberPassword = '" + SubPassword + "'"
14
15 Dim cmd As SqlClient.SqlCommand = New SqlCommand(selectString, cn)
16
17 Dim reader As SqlDataReader
18 reader = cmd.ExecuteReader
19 While reader.Read()
20 sID = reader("SubscriberID")
21 End While
22 Session("SubscriberID") = sID
23
24 reader.Close()
25
26 rtsNewsletters.SelectedIndex = 1
27 rtsNewsletters.FindTabByText("Subscribe").Enabled = True
28 rmpNewsletters.SelectedIndex = 1
29
30 End Sub


 

 Thanks all,

Brett