Listing 1: ASP.NET Code-Behind
  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 
Button1.Click

    Dim strQuery As String
    Dim conn As System.Data.SqlClient.SqlConnection = New System.Data.SqlClient.SqlConnection

    conn.ConnectionString = "SERVER=(local);DATABASE=NORTHWIND;UID=sa;PWD=**;"

    Try
      conn.Open()
    Catch ex As Exception
      Response.Write("<BR> Validate your Connection String!")
    End Try

   'CALLOUT A
    strQuery = "SELECT * FROM UserInj WHERE userid='" & TextBox1.Text & "' AND password='" & 
TextBox2.Text & "'"
   'END CALLOUT A

    Dim cmd As System.Data.SqlClient.SqlCommand = New 
System.Data.SqlClient.SqlCommand(strQuery)
    cmd.Connection = conn
   
    Dim rdr As System.Data.SqlClient.SqlDataReader = cmd.ExecuteReader()
    If (rdr.Read()) Then
      lblResult.Text = "**User Authenticated, Welcome: " & rdr.Item(0)
    Else
      lblResult.Text = "--Invalid User--"
    End If
    rdr.Close()
    conn.Close()

  End Sub