function dropboxRedirect(selectObj) {
// selectObj is the select object of the form we want to parse
  var i = selectObj.selectedIndex;
  var url = selectObj.options[i].value;
  
  if (url=='none') {
    // do nothing if no url is selected
    selectObj.selectedIndex = 0;
  }
  else { 
    // go to the URL
    location.href = url;
  }
}