Have an Unbounce form redirect to different URLs based on a dropdown selection

dynamic-form.html

<script>
/*
Unbounce Community :: Tips & Scripts :: Dynamic Form Confirmation URL's Using Browser Redirects 
TS:0002-04-051
***********************
Do not remove this section. It helps our team track useage of external workarounds.
*/
  
  var url = $("#destination"); 
  var formDestination = document.getElementById('form_destination');  // Add ID of dropdown field
  
  // Add URLs for dropdown options
  destination1 = 'community.unbounce.com'; 
  destination2 = 'unbounce.com/blog/';
  destination3 = 'google.ca';
  
  $(formDestination).change(function() {
   if (formDestination.selectedIndex == 1) {
    $(url).val(destination1);   
   } else if (formDestination.selectedIndex == 2) {
    $(url).val(destination2);       
   } else if (formDestination.selectedIndex == 3) {
    $(url).val(destination3);               
   } 
  });
</script>