<form id=immissione name="immissione" action="elabora.php" method="post">
<fieldset>
  <legend>1° quesito</legend>
  <br>
  <label for="questiontest">Testo della domanda</label>
  <textarea name="questiontest" rows="8">
  </textarea>
  <p>
  <label for="risp1">Risposta n. 1</label>
  <textarea id"risp1" name="risp1">(1)
  </textarea>
  <label for="true">Corretta</label><input id="true1" name="true" type="radio">
  <p>
  <label for="risp2">Risposta n. 2</label>
  <textarea id"risp2" name="risp2">(2)
  </textarea>
  <label for="true">Corretta</label><input id="true2" name="true" type="radio">
  <p>
  <label for="risp3">Risposta n. 3</label>
  <textarea id"risp3" name="risp3">(3)
  </textarea>
  <label for="true">Corretta</label><input id="true3" name="true" type="radio">
  <p>
  <label for="risp4">Risposta n. 4</label>
  <textarea id"risp4" name="risp4">(4)
  </textarea>
  <label for="true">Corretta</label><input id="true4" name="true" type="radio">
  <p>
  <label for="risp5">Risposta n. 5</label>
  <textarea id"risp5" name="risp5">(5)
  </textarea>
  <label for="true">Corretta</label><input id="true5" name="true" type="radio">
  <p>
  <textarea id"risptrue" name="risptrue" style="display:none;">
  </textarea>
</fieldset>
<fieldset>
  <legend>2° quesito</legend>
  <br>
  <label for="questiontest">Testo della domanda</label>
  <textarea name="questiontest2" rows="8">
  </textarea>
  <p>
  <label for="risp1">Risposta n. 1</label>
  <textarea id"risp1(2)" name="risp1(2)">(1)
  </textarea>
  <label for="true">Corretta</label><input id="true1(2)" name="true(2)" type="radio">
  <p>
  <label for="risp2">Risposta n. 2</label>
  <textarea id"risp2(2)" name="risp2(2)">(2)
  </textarea>
  <label for="true">Corretta</label><input id="true2(2)" name="true(2)" type="radio">
  <p>
  <label for="risp3">Risposta n. 3</label>
  <textarea id"risp3(2)" name="risp3(2)">(3)
  </textarea>
  <label for="true">Corretta</label><input id="true3(2)" name="true(2)" type="radio">
  <p>
  <label for="risp4">Risposta n. 4</label>
  <textarea id"risp4(2)" name="risp4(2)">(4)
  </textarea>
  <label for="true">Corretta</label><input id="true4(2)" name="true(2)" type="radio">
  <p>
  <label for="risp5">Risposta n. 5</label>
  <textarea id"risp5(2)" name="risp5(2)">(5)
  </textarea>
  <label for="true">Corretta</label><input id="true5(2)" name="true(2)" type="radio">
  <p>
  <textarea id"risptrue" name="risptrue(2)" style="display:none;">
  </textarea>
</fieldset>


...

</form>

$count = 1;

  <label for="risp<?php echo '$count'; ?>">Risposta n. <?php echo "$count"; ?></label>
  <textarea id"risp<?php echo "$count"; ?>" name="risp<?php echo "$count"; ?>">(<?php echo "$count"; ?>)
  </textarea>
  <label for="true">Corretta</label>

<?php
    $nQuesiti=20;
    for($i=1; $i<=$nQuesiti; $i++)
    {
?>
    <fieldset>
    <legend><?php echo $i; ?>° quesito</legend>
    <br>
    <label for="questiontest_<?php echo $i; ?>">Testo della domanda</label>
    <textarea name="questiontest_<?php echo $i; ?>" rows="8">
    </textarea>
    <p>
    <label for="risp1">Risposta n. 1</label>
    <textarea id="risp1_<?php echo $i; ?>" name="risp1_<?php echo $i; ?>">(1)
    </textarea>
    <label for="true">Corretta</label><input id="true1_<?php echo $i; ?>" name="true_<?php echo $i; ?>" type="radio">
    <p>
    <label for="risp2_<?php echo $i; ?>">Risposta n. 2</label>
    <textarea id="risp2_<?php echo $i; ?>" name="risp2_<?php echo $i; ?>">(2)
    </textarea>
    <label for="true">Corretta</label><input id="true2_<?php echo $i; ?>" name="true_<?php echo $i; ?>" type="radio">
    <p>
    <label for="risp3_<?php echo $i; ?>">Risposta n. 3</label>
    <textarea id="risp3_<?php echo $i; ?>" name="risp3_<?php echo $i; ?>">(3)
    </textarea>
    <label for="true">Corretta</label><input id="true3_<?php echo $i; ?>" name="true_<?php echo $i; ?>" type="radio">
    <p>
    <label for="risp4_<?php echo $i; ?>">Risposta n. 4</label>
    <textarea id="risp4_<?php echo $i; ?>" name="risp4_<?php echo $i; ?>">(4)
    </textarea>
    <label for="true">Corretta</label><input id="true4_<?php echo $i; ?>" name="true_<?php echo $i; ?>" type="radio">
    <p>
    <label for="risp5_<?php echo $i; ?>">Risposta n. 5</label>
    <textarea id="risp5_<?php echo $i; ?>" name="risp5_<?php echo $i; ?>">(5)
    </textarea>
    <label for="true">Corretta</label><input id="true5_<?php echo $i; ?>" name="true_<?php echo $i; ?>" type="radio">
    <p>
    <textarea id="risptrue_<?php echo $i; ?>" name="risptrue_<?php echo $i; ?>" style="display:none;">
    </textarea>
    </fieldset>
<?php
    }
?>