表格字体颜色点击变化

<script>
 function onFont(tid){
  for(var i = 1 ; ; i ++ ){
   var tfont = document.getElementById("font"+i);
   if(tfont){
    tfont.color = "black"; 
   } else {
    break;
   }
  }
  var tfont = document.getElementById("font"+tid);
  if(tfont){
   tfont.color="red"; 
  }
 }
</script>

<table border="1">
 <tr>
  <td><a href="javascript:onFont('1');"><font id="font1" color="red">aaa</font></a></td>
  <td><a href="javascript:onFont('2');"><font id="font2" color="black">bbb</font></a></td>
  <td><a href="javascript:onFont('3');"><font id="font3" color="black">ccc</font></a></td>
  <td><a href="javascript:onFont('4');"><font id="font4" color="black">ddd</font></a></td>
  <td><a href="javascript:onFont('5');"><font id="font5" color="black">eee</font></a></td>
 </tr>
</table>