单击提交按钮时，弹出的联系表单消失

Question

该表单基于引导程序，此处为代码：

当我尝试验证使用此非常简单的代码的提交时。 然后表格就消失了。任何见解的家伙将不胜感激。 谢谢 新gal要编码。

<div class="container">
  <div class="row">
    <div class="col-sm-12 contact-form">
      <form id="contact" method="post" class="form" role="form">
        <div class="row">
          <div class="col-xs-6 col-md-6 form-group">
            <input class="form-control" id="name" name="name" placeholder="FIRST NAME" type="text" required autofocus />
          </div>
          <div class="col-xs-6 col-md-6 form-group">
            <input class="form-control" id="name" name="lastname" placeholder="LAST NAME" type="text" required
              autofocus />
          </div>
          <div class="col-xs-6 col-md-6 form-group">
            <input class="form-control" id="email" name="email" placeholder="EMAIL" type="email" required />
          </div>
          <div class="col-xs-6 col-md-6 form-group">
            <input class="form-control" id="name" name="phone" placeholder="PHONE" type="text" required autofocus />
          </div>
          <div class="col-xs-6 col-md-6 form-group">
            <input class="form-control" id="name" name="address1" placeholder="ADDRESS 1" type="text" required
              autofocus />
          </div>
          <div class="col-xs-6 col-md-6 form-group">
            <input class="form-control" id="name" name="address2" placeholder="ADDRESS 2" type="text" required
              autofocus />
          </div>
          <div class="col-xs-6 col-md-6 form-group">
            <input class="form-control" id="name" name="city" placeholder="CITY" type="text" required autofocus />
          </div>
          <div class="col-xs-3 col-md-3 form-group">
            <input class="form-control" id="name" name="state" placeholder="STATE" type="text" required autofocus />
          </div>
          <div class="col-xs-3 col-md-3 form-group">
            <input class="form-control" id="name" name="zipcode" placeholder="ZIPCODE" type="text" required autofocus />
          </div>
          <h1 class="h1-contact">WHAT SERVICES ARE YOU INTERESTED IN?</h1>
        </div>
        <div class="row">
          <div class="col-sm-6">
            <h3>SELECT ALL THAT APPLY:</h3>
            <label class="checkbtn">item 1
              <input type="checkbox" checked="checked" name="item5" value="item5">
              <span class="checkmark"></span>
            </label>
            <label class="checkbtn"> item 2
              <input type="checkbox" name="item4" id="item4">
              <span class="checkmark"></span>
            </label>
            <label class="checkbtn">item 3
              <input type="checkbox" name="item3" id="item3">
              <span class="checkmark"></span>
            </label>
            <label class="checkbtn">item 4
              <input type="checkbox" name="item2" id="item2">
              <span class="checkmark"></span>
            </label>
            <label class="checkbtn">item 5
              <input type="checkbox" name="example1">
              <span class="checkmark"></span>