JavaScript实现Table表格隔行变色

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>table间隔色</title>
<script type="text/javascript">
function SetTableColor() {
  var tbl = document.getElementById("tblMain");
  var trs = tbl.getElementsByTagName("tr");
  for (var i = 0; i < trs.length; i++) {
 var j = i + 1;
 if (j % 2 == 0) { //偶数行
   trs[i].style.background = "yellow";
 }
 else {
   trs[i].style.background = "blue";
 }
  }
}
</script>
</head>
<body onload="SetTableColor()">
<table id="tblMain" border="1">
<tr>
  <td>1</td>
  <td>三星</td>
  <td>AA</td>
</tr>
<tr>
  <td>2</td>
  <td>Norkia</td>
  <td>BB</td>
</tr>
<tr>
  <td>3</td>
  <td>苹果</td>
  <td>CC</td>
</tr>
<tr>
  <td>4</td>
  <td>联想</td>
  <td>DD</td>
</tr>
<tr>
  <td>5</td>
  <td>小米</td>
  <td>EE</td>
</tr>
<tr>
  <td>6</td>
  <td>HTC</td>
  <td>FF</td>
</tr>
</table>
</body>
</html>