private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
lblSerwer.Enabled = chbProxy.Checked;
lbPort.Enabled = chbProxy.Checked;
txtLogin.Enabled = chbProxy.Checked;
txtHaslo.Enabled = chbProxy.Checked;
chbUwierzytelnienie.Enabled = chbProxy.Checked;
}