根据单选按钮显示div (带POST)

<form id="myForm" action="backend.php" method="POST">
  <input type="radio" name="option" value="option1" onclick="showDiv('div1')"> Option 1
  <input type="radio" name="option" value="option2" onclick="showDiv('div2')"> Option 2
  <input type="radio" name="option" value="option3" onclick="showDiv('div3')"> Option 3
</form>

<div id="div1" style="display:none;">This is div 1</div>
<div id="div2" style="display:none;">This is div 2</div>
<div id="div3" style="display:none;">This is div 3</div>

function showDiv(divId) {
  var div = document.getElementById(divId);
  var divs = document.getElementsByTagName("div");
  
  for (var i = 0; i < divs.length; i++) {
    divs[i].style.display = "none";
  }
  
  div.style.display = "block";
  
  // 将选择的值设置到隐藏的input元素中
  var optionValue = divId.replace("div", "");
  var hiddenInput = document.createElement("input");
  hiddenInput.type = "hidden";
  hiddenInput.name = "selectedOption";
  hiddenInput.value = optionValue;
  
  var form = document.getElementById("myForm");
  form.appendChild(hiddenInput);
  
  // 提交表单
  form.submit();
}