<form class="modal-content" id="bookingForm">    <div class="formContainer">      <h1>Booking Form</h1>      <p>Please fill in this form to Book The Trip.</p>      <hr>      <label for="email"><b>Email</b></label>      <input type="text" placeholder="Enter Email" name="email" required id="email">      <label><b>Package</b></label>      <input type="text" id="packageFields" name="teste2">      <label for="psw"><b>Name</b></label>      <input type="text" placeholder="Enter Name" name="name" required id="name">      <label for="psw-repeat"><b>Phone No.</b></label>      <input type="tel" placeholder="Enter Phone No." name="psw-repeat" required id="phone">      <label for="psw-repeat"><b>Date Of Journey</b></label>      <input type="date" placeholder="Enter Phone No." name="psw-repeat" required id="date">      <p>By creating an account you agree to our <a href="#" style="color:dodgerblue">Terms & Privacy</a>.</p>      <div class="clearfix">        <button type="submit" class="signupbtn">Confirm Booking</button>        <button type="button" onclick="document.getElementById('bookingForm').style.display='none'" class="cancelbtn">Cancel</button>      </div>    </div>  </form>我正在嘗試將我的聯系人表單的數據存儲在火庫中。但它給出了錯誤未捕獲的打字錯誤： 提交預訂時為空提交.js：27我把腳本放在最后，那么為什么它給出這個錯誤？它的原因是什么，如何解決它...？？