ASP.Net: Get Length of Byte Array in VB.Net

hi

how get value bytes image from image which save in table when query running like this code, display messagebox values bytes

Using koneksi As New SqlConnection(ambilstringkoneksi)
    Dim perintah As SqlCommand = New SqlCommand("select * from tempimage where idp='123'", koneksi)
    perintah.CommandType = CommandType.Text
    koneksi.Open()
    Dim myreader As SqlDataReader = perintah.ExecuteReader(CommandBehavior.CloseConnection)
    If myreader.Read() Then
        Dim bytes() As Byte = CType(myreader("img"), Byte())
        Response.Cache.SetCacheability(HttpCacheability.NoCache)
        Response.BinaryWrite(bytes)
        Response.Flush()
        Response.End()
    Else
        MsgBox("data not found")
    End If
    myreader.Close()
    koneksi.Close()
End Using

thanks