$search_columns = array('user_email');
elseif ( is_numeric($search) )
$search_columns = array('user_login', 'ID');
$search_columns = array('user_email');
elseif ( is_numeric($search) )
$search_columns = array('user_login', 'ID');
$search_columns = array('user_url');
else
$search_columns = array('user_login', 'user_nicename');
$search_columns = array('user_url');
else
$search_columns = array('user_login', 'user_nicename');