Не вводятся данные с формы

<?php 
    $hostname="localhost"; 
    $username="root"; 
    $password=""; 
    $dbName="diplom";  
    $link = mysqli_connect($hostname,$username,$password) or die("No connect"); 
    if (mysqli_connect_errno()) {
        printf("Ошибка подключения к БД", mysqli_connect_error());
        exit();
    }
    mysqli_set_charset($link, 'utf8' );
    mysqli_select_db($link, $dbName);
?>
      <form method="post" action="index.php">
           Имя<br/><input type="text" name="name"><br/>
           Фамилия<br/><input type="text" name="surname"><br/>
           Отчество<br/><input type="text" name="father"><br/>
           Группа<br/><input type="text" name="groyp"><br/>
          <input type="submit" name="send" value="Добавить студента">
         </form>
    <?php
    if ($_SERVER['REQUEST_METHOD'] == 'POST') {
        $name = $_POST['name'];
        $surname = $_POST['surname'];
        $father = $_POST['father'];
        $groyp = $_POST['groyp'];
        mysqli_query($link, "select * FROM student");
        mysqli_query($link, "INSERT INTO 'student' ('name', 'surname', 'father', 'groyp') 
          VALUES ('$name', '$surname', '$father', '$groyp')"); 
    ?>