How to use javascript up and down arrow keys to control table row selection and highlighting_javascript skills

The example in this article describes how to use the JavaScript up and down arrow keys to control the selection and highlighting of table rows. Share it with everyone for your reference. The specific implementation method is as follows:

<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>

I hope this article will be helpful to everyone’s JavaScript programming design.