Saving drawn image problem C# GUI

<pre>
private void openToolStripMenuItem_Click(object sender, EventArgs e)
        {
            openFileDialog1.Title = "Open an image";
            openFileDialog1.Filter = "JPEG|*.jpeg|GIF|*.gif|BMP|*.bmp|TIFF|*.tiff|PNG|*.png|JPG|*.jpg";
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                try
                {
                    file = Image.FromFile(openFileDialog1.FileName);
                    pictureBox1.Image = file;
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            } 
        }

<pre lang="c#">
private void saveToolStripMenuItem_Click(object sender, EventArgs e)
        {

            saveFileDialog1.Title = "Save image";
            saveFileDialog1.Filter = "BMP|.bmp|JPEG|*.jpeg";
            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                try
                {
                    file.Save(saveFileDialog1.FileName);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }