private void saveAsToolStripMenuItem_Click(object sender, EventArgs e)
{
// save graph as image
SaveFileDialog sfd = new SaveFileDialog();
sfd.Filter = "JPEG images|*.jpg";
if (sfd.ShowDialog() == DialogResult.OK)
{
chartControl1.ExportToImage(sfd.FileName, System.Drawing.Imaging.ImageFormat.Jpeg);
}
}