Verifying Entry Is Not In DB B4 Inserting

How do i do that... in sch lab, the lecturer said:
    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

        Try

            SqlDataSource2.SelectParameters("Title").DefaultValue = txtProductTitle.Text
            GridView1.DataBind()

            If GridView1.Rows.Count > 0 Then //if no repeated
                Label1.Text = "Existing Record Found. Please enter another Software."
            Else
                'SqlDataSource1.Insert()
                'Label1.Text = txtProductTitle.Text & " successfully added to the database."
            End If
        Catch ex As Exception
            Label1.ForeColor = Drawing.Color.Red
            Label1.Text = "An error occured!" & ControlChars.NewLine & ControlChars.NewLine & _
            ex.Message.ToString()
        End Try

    End Sub
but its not working for me... the GridView1.Rows.Count is always 0, if there is a repeat, it should be > 0