private void UseProxyCheckBox_CheckedChanged(object sender, EventArgs e)
{
ProxyAddressTextBox.Enabled = UseProxyCheckBox.Checked;
ProxyPortTextBox.Enabled = UseProxyCheckBox.Checked;
ProxyUserTextBox.Enabled = UseProxyCheckBox.Checked;
ProxyPassTextBox.Enabled = UseProxyCheckBox.Checked;
}