private void otwórzToolStripMenuItem_Click(object sender, EventArgs e)
{
if (openFileDialog1.ShowDialog() != DialogResult.OK)
return;
PictureForm picture = new PictureForm(this
);
picture.MdiParent = this;
picture.Text = new StringBuilder("Obraz ").Append(++formCounter).ToString();
picture.loadImage(openFileDialog1.FileName);
picture.Show();
}