javascript上下方向键控制表格行选中并高亮显示的方法

<style>

tr.highlight {

 background:#08246B;

 color:white;

}

</style>

<table border="1" width="70%" id="ice">

 <tr onClick="selectTR();return false;">

  <td>123</td>

  <td>234</td>

  <td>abc</td>

  <td>def</td>

 </tr>

 <tr onClick="selectTR();">

  <td>123</td>

  <td>234</td>

  <td>abc</td>

  <td>def</td>

 </tr>

 <tr onClick="selectTR();">

  <td>123</td>

  <td>234</td>

  <td>abc</td>

  <td>def</td>

 </tr>

 <tr onClick="selectTR();">

  <td>123</td>

  <td>234</td>

  <td>abc</td>

  <td>def</td>

 </tr>

 <tr onClick="selectTR();">

  <td>123</td>

  <td>234</td>

  <td>abc</td>

  <td>def</td>

 </tr>

</table>

<script language="javascript"> 

<!-- 

var currentLine = -1; 

document.onkeydown = function(e)  

{ 

  e = window.event || e; 

  switch(e.keyCode)  

  { 

    case 38: 

      currentLine--; 

      changeItem(); 

      break; 

    case 40: 

      currentLine++; 

      changeItem(); 

      break; 

    default: 

      break; 

  } 

} 

function selectTR()

{

 currentLine=window.event.srcElement.parentElement.rowIndex;

 //alert(currentLine);

 changeItem();

}

//改变选择项目 

function changeItem() 

{ 

  if(document.all) 

    var it = document.getElementById("ice").children[0]; 

  else 

    var it = document.getElementById("ice");



  for(i=0;i<it.rows.length;i++)  

  { 

    it.rows[i].className = ""; 

  } 

  if(currentLine < 0) 

    currentLine = it.rows.length - 1; 

  if(currentLine == it.rows.length) 

    currentLine = 0; 

  it.rows[currentLine].className = "highlight"; 

} 

//--> 

</script>