code: private static void openDialog(String uploadTarget) {
  
          try {
              A_CmsUploadDialog dialog = GWT.create(CmsUploadDialogImpl.class);
              dialog.setContext(new I_CmsUploadContext() {
  
                  public void onUploadFinished(List<String> uploadedFiles) {
  
                      Window.Location.reload();
                  }
              });
              dialog.setTargetFolder(uploadTarget);
              dialog.loadAndShow();
          } catch (Exception e) {
              CmsErrorDialog.handleException(
                  new Exception(
                      "Deserialization of dialog data failed. This may be caused by expired java-script resources, please clear your browser cache and try again.",
                      e));
          }
      }
docs: Opens an empty upload dialog.<p>
  
  @param uploadTarget the target folder