问表单保存空值php

EN

<form   action=""   method="POST"  >    

<?php

if ( isset($_GET['success']) === true && empty($_GET['success'])===true ){
   echo'Profile Updated Sucessfuly';
    }else{
   if( empty($_POST) === false  &&  empty($errors) === true ){
     $update_data_profile = array('telephone' => $_POST['telephone']);

          update_user_profile($session_user_id, $update_data_profile);
      header('Location: profile_update.php?success');                               
      exit();

   }else if ( empty($errors) === false ){
      echo output_errors($errors);
       }

     ?>

 Telephone<input name="telephone" type="text" size="25"  value="<?php echo $user_data_profile['telephone']; ?>"/>
<input type="submit" value="" name="submit"/>
</form> 

function update_user_profile($user_id, $update_data_profile){

  $result = mysql_query("select user_id from profile where user_id = $user_id limit 1");

  if(mysql_num_rows($result) === 1){

  $update = array();
      array_walk($update_data_profile, 'array_sanitize');

  foreach($update_data_profile as $field => $data ){
    if(!empty($data)){
      $update[]='`' . $field . '` = \'' . $data . '\'';
    }
  }

  if(isset($update) && !empty($update)){

  mysql_query(" UPDATE `profile` SET " . implode(',  ', $update) . " WHERE `user_id` = $user_id ") or die(mysql_error());
}
   }
  else{

$user_id = $update_data_profile['user_id'] ;

if(count($update_data_profile)){

$columns = array();
$values = array();

    foreach($update_data_profile as $field => $data){
    $columns[] = $field;
    $values[] = $data;
    } 
}

mysql_query(" INSERT INTO `profile` (" . implode(",", $columns) .") values ('" . implode("','", $values) . "')" ) or die (mysql_error());

}

}