PdfFormField barcode = PdfFormField.createPushButton(writer);
barcode.setFieldName("barcode");
cell.setCellEvent(new StudentCardForm(barcode));
outertable.addCell(cell);
outertable.writeSelectedRows(0, -1, 20, 100, writer.getDirectContent());
writer.addAnnotation(name);
writer.addAnnotation(birthdate);
writer.addAnnotation(studyprogram);
writer.addAnnotation(option);
writer.addAnnotation(picture);
writer.addAnnotation(barcode);