The following can be implemented to get the user details
global $user;
$user_load = user_load($user->uid);
$user_load->field_f_name[LANGUAGE_NONE][0]['value'] ;
$user$user_load->field_l_name[LANGUAGE_NONE][0]['value'] ;
$user$user_load->field_phone[LANGUAGE_NONE][0]['value'] ;
$user$user_load->field_address[LANGUAGE_NONE][0]['value']