如何使HTML表单按特定条件显示字段？

<form>
  <label for="condition">条件：</label>
  <select id="condition" onchange="toggleFields()">
    <option value="option1">选项1</option>
    <option value="option2">选项2</option>
  </select>
  
  <div id="field1" style="display: none;">
    <label for="field1Input">字段1：</label>
    <input type="text" id="field1Input">
  </div>
  
  <div id="field2" style="display: none;">
    <label for="field2Input">字段2：</label>
    <input type="text" id="field2Input">
  </div>
  
  <input type="submit" value="提交">
</form>

function toggleFields() {
  var condition = document.getElementById("condition").value;
  
  if (condition === "option1") {
    document.getElementById("field1").style.display = "block";
    document.getElementById("field2").style.display = "none";
  } else if (condition === "option2") {
    document.getElementById("field1").style.display = "none";
    document.getElementById("field2").style.display = "block";
  }
}

window.onload = function() {
  toggleFields();
};