path.postedfile is not working

System.Drawing.Image imageToBeResized = System.Drawing.Image.FromStream(path.PostedFile.InputStream);
                int imageHeight = imageToBeResized.Height;
                int imageWidth = imageToBeResized.Width;
                int maxHeight = 400;
                int maxWidth = 400;
                imageHeight = (imageHeight * maxWidth) / imageWidth;
                imageWidth = maxWidth;

                if (imageHeight > maxHeight)
                    {
                    imageWidth = (imageWidth * maxHeight) / imageHeight;
                    imageHeight = maxHeight;
                    }

                Bitmap bitmap = new Bitmap(imageToBeResized, imageWidth, imageHeight);
                System.IO.MemoryStream stream = new MemoryStream();
                bitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Jpeg);
                stream.Position = 0;
                byte[] imasave = new byte[stream.Length + 1];
                stream.Read(imasave , 0, imasave.Length);


                file.SaveAs(imasave);