如何通过id获取span元素？

Question

实际上，我创建了一个带有关闭图标的弹出窗口，并且我尝试使用span方法关闭弹出窗口。我想通过元素ID获取跨度元素值。       <script>  // 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")[1];  // 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";    }  }  </script>