private void button_printout_Click(object sender, EventArgs e)
{
errorProvider1.Dispose();
backColor_change();
button_printout.BackColor = Color.SteelBlue;
form_hide();
print.TopLevel = false;
panel_main.Controls.Add(print);
print.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
print.Show();
}
