$form_data = array();
$form_data['values']['firstname'] = $user->field_civilite['und'][0]['tid'];
$form_data['values']['lastname'] = $user->field_prenom['und'][0]['value'];
$form_data['values']['mail'] = $user->field_nom['und'][0]['value'];

webform_client_form_submit(226, $form_data);

$node = node_load($nid); //nid is the node id of your webform
  global $user;

 //the values to save
  $data = array(
    1 => array('value' => array($first_value)),
    2 => array('value' => array($second_value)),
  );

  $submission = (object) array(
    'nid' => $nid,
    'uid' => $user->uid,
    'submitted' => REQUEST_TIME,
    'remote_addr' => ip_address(),
    'is_draft' => FALSE,
    'data' => $data,
  );

  module_load_include('inc', 'webform', 'includes/webform.submissions');
  webform_submission_insert($node, $submission);
  webform_submission_send_mail($node, $submission);