使用html时，我可以将用户的输入添加到onclick =“return confirm”吗？

Question

Is it possible to add something a user wrote or selected to a confirm window (onclick="return confirm) before its sent to a script to process? If possible only with php and html.

     <form action="store.php" method="POST">
  <select name="day">
    <option value="" disabled selected>Tag</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
    <option value="5">5</option>
  </select>
  <select name="month">
    <option value="" disabled selected>Monat</option>
    <option value="Januar">Januar</option>
    <option value="Febraur">Febraur</option>
    <option value="März">März</option>
  </select>
  <select name="year">
    <?php
      $year = date("Y");
      $nextyear = $year + 1;
      $month = date("n");
      if ($month >= 8) {
        echo "<option value='' disabled selected>Jahr</option><option value=".$year.">".$year."</option><option value=".$nextyear.">".$snextyear."</option>";
      }else {
        echo "<option value=".$syear.">".$syear."</option>";
      }
     ?>
  </select>
  <input type="text" name="exam" placeholder="Prüfung"/>
  <input type="submit" onclick="return confirm('Are you sure?')"/>
</form>

Answer 1

So read the value of the input[s] and put it in the string.

function confirmSubmit() {
   var form = document.forms[0],  //reference the form
       year = form.year.value,    //get the input values
       exam = form.exam.value;
   return confirm("your string " + year + " " + exam);  //string concatenation
}

     <form action="" method="POST">
  <select name="day">
    <option value="" disabled selected>Tag</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
    <option value="5">5</option>
  </select>
  <select name="month">
    <option value="" disabled selected>Monat</option>
    <option value="Januar">Januar</option>
    <option value="Febraur">Febraur</option>
    <option value="März">März</option>
  </select>
  <select name="year">
    <option>1</option>
    <option>2</option>
    <option>3</option>
  </select>
  <input type="text" name="exam" placeholder="Prüfung"/>
  <input type="submit" onclick="return confirmSubmit()"/>
</form>

</div>