Make Bitmap On Startup 2

using System.Drawing;

void New_file(PictureBox pb)
{
bmp_image = newBitmap(pb.Width, pb.Height);
g = Graphics.FromImage(bmp_image);
g.FillRectangle(Brushes.White, newRectangle(0, 0, bmp_image.Width, bmp_image.Height));
pb.Image = bmp_image;
}