export story in button click

Hi

I don't know why but when i want to export incopy inside button click event it don't work

How to export file after button click

closeBtn.onClick = function() {

  var stories =  getStories(app.selection); // get all selection stories

  for (var i = 0; i < stories.length; i++) {

      var abc = stories.exportFile(ExportFormat.INCOPY_MARKUP,'c:\\1\\tmp.icml');

  }

    artDialog.close();

  }

Thanks