根据值不起作用选择下拉项

<select id="mySelect" onchange="selectChange()">
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
</select>

<div id="result"></div>

function selectChange() {
  var select = document.getElementById("mySelect");
  var selectedValue = select.value;
  
  var resultDiv = document.getElementById("result");
  
  if (selectedValue === "option1") {
    resultDiv.innerHTML = "你选择了选项1";
  } else if (selectedValue === "option2") {
    resultDiv.innerHTML = "你选择了选项2";
  } else if (selectedValue === "option3") {
    resultDiv.innerHTML = "你选择了选项3";
  }
}