我如何保持用户输入后关闭模态在同一页面没有重新加载

我希望能够保持用户在模态的复选框中决定的数据，并在模态之外发送复选框决定，而无需离开页面或重新加载。

如果用户决定在模态中选中复选框，当我按下continue然后等待提交按钮发送所有复选框的值时，我如何保存该数据?

var btn = document.getElementById("myBtn");
// Get the modal
var modal = document.getElementById('myModal');
// Get the button that opens the modal
var btn = document.getElementById("myBtn");
// Get the <span> element that closes the modal
var span = document.getElementsByClassName("close")[0];
// When the user clicks the button, open the modal
btn.onclick = function() {
  modal.style.display = "block";
}
// When the user clicks on <span> (x), close the modal
span.onclick = function() {
  modal.style.display = "none";
}
// When the user clicks anywhere outside of the modal, close it
window.onclick = function(event) {
  if (event.target == modal) {
    modal.style.display = "none";
  }
}

/* The Modal (background) */
.modal {
  display: none;
  /* Hidden by default */
  position: fixed;
  /* Stay in place */
  z-index: 1;
  /* Sit on top */
  padding-top: 100px;
  /* Location of the box */
  left: 0;
  top: 0;
  width: 100%;
  /* Full width */
  height: 100%;
  /* Full height */
  overflow: auto;
  /* Enable scroll if needed */
  background-color: rgb(0, 0, 0);
  /* Fallback color */
  background-color: rgba(0, 0, 0, 0.4);
  /* Black w/ opacity */
}
/* Modal Content */
.modal-content {
  position: relative;
  background-color: #fefefe;
  margin: auto;
  padding: 0;
  border: 1px solid #888;
  width: 80%;
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
  -webkit-animation-name: animatetop;
  -webkit-animation-duration: 0.4s;
  animation-name: animatetop;
  animation-duration: 0.4s
}
/* Add Animation */
@-webkit-keyframes animatetop {
  from {
    top: -300px;
    opacity: 0
  }
  to {
    top: 0;
    opacity: 1
  }
}
@keyframes animatetop {
  from {
    top: -300px;
    opacity: 0
  }
  to {
    top: 0;
    opacity: 1
  }
}
/* The Close Button */
.close {
  color: white;
  float: right;
  font-size: 28px;
  font-weight: bold;
}
.close:hover,
.close:focus {
  color: #000;
  text-decoration: none;
  cursor: pointer;
}
.modal-header {
  padding: 2px 16px;
  background-color: #5cb85c;
  color: white;
}
.modal-body {
  padding: 2px 16px;
}
.modal-footer {
  padding: 2px 16px;
  background-color: #5cb85c;
  color: white;
}

<!-- Trigger/Open The Modal -->
<button id="myBtn">Open Modal</button>
<!-- The Modal -->
<div id="myModal" class="modal">
  <!-- Modal content -->
  <div class="modal-content">
    <div class="modal-header">
      <span class="close">×</span>
      <h2>Modal Header</h2>
    </div>
    <div class="modal-body">
      <p>Some text in the Modal Body</p>
      <p>Some other text...</p>
    </div>
    <div class="modal-footer">
      <h3>Modal Footer</h3>
      <input type="checkbox" name="option" />
      <input type="submit" value="continue" />
    </div>
  </div>
</div>
<div>
  <input type="checkbox" name="value" />
  <input type="submit" value="Send" />
</div>