openid_user_add_validate($form, &$form_state)modules/openid/openid.pages.inc, line 80
<?php
function openid_user_add_validate($form, &$form_state) {
// Check for existing entries.
$claimed_id = openid_normalize($form_state['values']['openid_identifier']);
if (db_query("SELECT authname FROM {authmap} WHERE authname = :authname", (array(':authname' => $claimed_id)))->fetchField()) {
form_set_error('openid_identifier', t('That OpenID is already in use on this site.'));
}
}
?>