Issue with JavaScript Code for Dropdown Interaction in Adobe Acrobat

I am experiencing an issue with a JavaScript code snippet that I am using to link two dropdown fields in Adobe Acrobat. I have a "Dropdown1" dropdown and a "Dropdown2" dropdown, and I want the selection in the "Dropdown1" dropdown to automatically update the value in the "Dropdown2" dropdown.

I have followed the instructions provided and tried different code snippets, but the functionality is not working as expected. When I select an option in the "Dropdown1" dropdown, the corresponding value does not update in the "Dropdown2" dropdown.

Steps taken:

1. Verified the field names used in the JavaScript code and ensured they match the actual field names in the PDF document.
2. Confirmed that JavaScript execution is enabled in my PDF viewer.
3. Tested the PDF document in different viewers to check for any compatibility issues.
4. Checked for conflicting scripts or actions that may interfere with the dropdown functionality.
5. Ensured that I am using the latest version of Adobe Acrobat.

Despite these efforts, I have been unable to resolve the issue. I am seeking assistance in identifying the problem and finding a solution for the dropdown interaction.

var carDropdown = this.getField("Dropdown1");
var carIDDropdown = this.getField("Dropdown2");

carDropdown.setAction("OnBlur", "updateCarID()");

function updateCarID() {
  var selectedCar = carDropdown.value;

  switch (selectedCar) {
    case "USA":
      carIDDropdown.value = "USA";
      break;
    case "CANADA":
      carIDDropdown.value = "CANADA";
      break;
    case "Greenland":
      carIDDropdown.value = "Greenland";
      break;
    case "Iceland":
      carIDDropdown.value = "Iceland";
      break;
    default:
      carIDDropdown.value = "";
      break;
  }
}

Any guidance or insights into this issue would be greatly appreciated. Thank you in advance for your assistance.