<table>
  <tr onclick="SetBackGround(this)"><td>1</td><td>2</td><td>3</td></tr>
  <tr onclick="SetBackGround(this)"><td>4</td><td>5</td><td>6</td></tr>
  <tr onclick="SetBackGround(this)"><td>7</td><td>8</td><td>9</td></tr>
</table>
<script>
  function SetBackGround(sender)
  {
    var cells = sender.getElementsByTagName("td");
    for (var i = 0; i <= cells.length - 1;i++) 
    {
      cells[i].style.backgroundColor = "#b9ffb9";
    }
  }
</script>