possible uploadify solution

$(document).ready(function() {
  $('#report_upload').uploadify({
  'uploader'  : '/uploadify.swf',
  'script': '<%= url_for(:action => :create) %>',
  'cancelImg' : '/images/cancel.png',
  'auto' : false,
  'fileDataName' : 'report[upload]',
  'onComplete' : function() {window.location = "<%= users_path %>"},
  'scriptData' : {
    'report[upload_type]' : function() {$('#report_upload_type').val()}(),
    'report[client_id]' : $('#report_client_id').val(),
    '<%= session_key_name %>' : encodeURIComponent('<%= u cookies[session_key_name] %>'),
    'authenticity_token' : encodeURIComponent('<%= u form_authenticity_token %>')}
  });
  
  $("#report_upload_type").change(function(){
    $('#report_upload').uploadifySettings('scriptData', {
      'report[upload_type]' : function() {$('#report_upload_type option:selected').val()}(),
      'report[client_id]' : $('#report_client_id').val(),
      '<%= session_key_name %>' : encodeURIComponent('<%= u cookies[session_key_name] %>'),
      'authenticity_token' : encodeURIComponent('<%= u form_authenticity_token %>')}
    });
  });
});