function enforce_rating(question_id, row_index) {
  var current_row = $("input[name^=questions\\[" + question_id + "\\]\\[" + row_index + "\\]]");
  var column_index = 0;
  for (var x = 0; x < current_row.length; ++x)
    if (current_row[x].checked)
      column_index = x;

  for (var x = 0; x < 255; ++x) {
    if (x == row_index) continue;
    var column = $("#questions_" + question_id + "_" + x + "_" + column_index);
    if (column.length > 0)
      column[0].checked = false;
  }
}