load image from Mysql :Parameter is not valid

[dre-logics]

myconn.Open()
        MySQLstring1 = "select picture from naw where id = 17"
        myCommand1.Connection = myconn
        myCommand1.CommandText = MySQLstring1
        myReader = myCommand1.ExecuteReader
        If Not myReader.HasRows Then
            MsgBox("now rows found")
            Exit Sub
        End If
       If myReader.Read Then
            Dim imgByteArray() As Byte
            imgByteArray = CType(myReader.Item("picture"), Byte())
            Dim MyStream As New System.IO.MemoryStream(imgByteArray)
            PictureBox1.Image = Image.FromStream(MyStream)            
              MyStream.Close()
                 End If

        myReader.Close()
        myconn.Close()