我在網(wǎng)站中使用表單，如果提交空白表單，用戶應(yīng)該收到錯(cuò)誤警報(bào)。我使用下面的 HTML 和 JS 將表單數(shù)據(jù)轉(zhuǎn)換為 JSON 并將其提交到電子郵件 API。但即使對(duì)于空白值，表單也會(huì)被提交，這是不應(yīng)該發(fā)生的。請(qǐng)幫我解決這個(gè)問題。TIA。<form name="ff" id="ff">  <label style="font-family: sans-serif;"></label> Name*:  <input type="text" placeholder="Please enter your name" name="name" id="name" required />  <label style="font-family: sans-serif;">    Email*:    <input type="email" placeholder="Enter your Email ID" name="email" id="email" required />  </label>  <label style="font-family: sans-serif;">    Mobile Number *:    <input type="text" placeholder="Enter Your Number" name="mobile" id="mobile" maxlength="10" required />  </label>  </label>  <label style="font-family: sans-serif;">    Message*:    <textarea name="message" id="message" cols="500" placeholder="Message" required></textarea>  </label>  <input id="contactbtn" class="sendButton" type="submit" name="Submit" value="Send" /></form>function getFormData($form) {  var unindexed_array = $form.serializeArray();  var indexed_array = {};  $.map(unindexed_array, function (n, i) {    indexed_array[n['name']] = n['value'];  });  return indexed_array;}var $form = $("#ff");$('#contactbtn').click(function (e) {  e.preventDefault();  var data = getFormData($form);  console.log(data);  localStorage.setItem('order', JSON.stringify(data));  console.log('order');  window.location.replace("./contactbooking.html");});