How Do I Avoid Repeating Data In My Project

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load

    If Not IsPostBack Then
        Try
            Dim daQuestions As New SqlDataAdapter("SELECT TOP 20 * FROM tblQuestions ORDER BY NEWID()", con)
            Dim dsQuestions As New Data.DataSet
            Dim dtQuestions As New Data.DataTable

            If Not con.State = Data.ConnectionState.Open Then con.Open()
            daQuestions.Fill(dsQuestions)
            dtQuestions = dsQuestions.Tables(0)

            If Not dtQuestions.Rows.Count <= 0 Then
                'For Question 1
                If Not IsDBNull(dtQuestions.Rows(0).Item("Question")) Then
                    lblQuestion1.Text = dtQuestions.Rows(0).Item("Question")
                End If
                If Not IsDBNull(dtQuestions.Rows(0).Item("Option1")) Then
                    rblQuestion1.Items(0).Text = dtQuestions.Rows(0).Item("Option1")
                End If
                If Not IsDBNull(dtQuestions.Rows(0).Item("Option2")) Then
                    rblQuestion1.Items(1).Text = dtQuestions.Rows(0).Item("Option2")
                End If
                If Not IsDBNull(dtQuestions.Rows(0).Item("Option3")) Then
                    rblQuestion1.Items(2).Text = dtQuestions.Rows(0).Item("Option3")
                End If
                If Not IsDBNull(dtQuestions.Rows(0).Item("Option4")) Then
                    rblQuestion1.Items(3).Text = dtQuestions.Rows(0).Item("Option4")
                End If
            End If
        Catch ex As Exception

        End Try




        'con.ConnectionString = ConfigurationManager.ConnectionStrings("DefaultConnection").ConnectionString
        cmd = New SqlCommand("insert into tblQuestions (Question, Option1, Option2, Option3, Option4,) values (@question, @option1, @option2, @option3, @option4)", con)
        cmd.Parameters.AddWithValue("@question", lblQuestion1.Text)
        cmd.Parameters.AddWithValue("@option1", rblQuestion1.Text)
        cmd.Parameters.AddWithValue("@option2", rblQuestion1.Text)
        cmd.Parameters.AddWithValue("@option3", rblQuestion1.Text)
        cmd.Parameters.AddWithValue("@option4", rblQuestion1.Text)
        'cmdInsertQuestion.Parameters.AddWithValue("@answer", txtAnswer.Text)
        Try
            con.Open()
            cmd.ExecuteNonQuery()
            con.Close()
            MsgBox(" ")
            'txtAnswer.Text = ""
            rblQuestion1.Text = ""
            rblQuestion1.Text = ""
            rblQuestion1.Text = ""
            rblQuestion1.Text = ""
        Catch ex As Exception
            'ex.Message
        End Try
    End If
End Sub



Protected Sub rblQuestion1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles rblQuestion1.SelectedIndexChanged

End Sub

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click


    If IsPostBack Then
        Try
            Dim daQuestions As New SqlDataAdapter("SELECT TOP 20 * FROM tblQuestions ORDER BY NEWID()", con)
            Dim dsQuestions As New Data.DataSet
            Dim dtQuestions As New Data.DataTable
            rblQuestion1.ClearSelection()
            If Not con.State = Data.ConnectionState.Open Then con.Open()
            daQuestions.Fill(dsQuestions)
            dtQuestions = dsQuestions.Tables(0)

            If Not dtQuestions.Rows.Count <= 0 Then

                If Not IsDBNull(dtQuestions.Rows(0).Item("Question")) Then
                    lblQuestion1.Text = dtQuestions.Rows(0).Item("Question")
                End If
                If Not IsDBNull(dtQuestions.Rows(0).Item("Option1")) Then
                    rblQuestion1.Items(0).Text = dtQuestions.Rows(0).Item("Option1")
                End If
                If Not IsDBNull(dtQuestions.Rows(0).Item("Option2")) Then
                    rblQuestion1.Items(1).Text = dtQuestions.Rows(0).Item("Option2")
                End If
                If Not IsDBNull(dtQuestions.Rows(0).Item("Option3")) Then
                    rblQuestion1.Items(2).Text = dtQuestions.Rows(0).Item("Option3")
                End If
                If Not IsDBNull(dtQuestions.Rows(0).Item("Option4")) Then
                    rblQuestion1.Items(3).Text = dtQuestions.Rows(0).Item("Option4")
                End If
            End If



        Catch ex As Exception

        End Try


    End If
End Sub



End Class