如何在提交后保留选中的onchange下拉列表值

<select id="mySelect" onchange="myFunction()">
  <option value="value1">Value 1</option>
  <option value="value2">Value 2</option>
  <option value="value3">Value 3</option>
</select>

function myFunction() {
  var selectedValue = document.getElementById("mySelect").value;
  localStorage.setItem("selectedValue", selectedValue);
}

window.onload = function() {
  var selectedValue = localStorage.getItem("selectedValue");
  if (selectedValue) {
    document.getElementById("mySelect").value = selectedValue;
  }
}