javascript模拟评分控件实现方法

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>动态设置style(评分效果)</title>
<script type="text/javascript">
//查找一个元素在数组中的索引位置
function ArrayIndexOf(arr, element) {
for (var i = 0; i < arr.length; i++) {
if (arr[i] == element) {
return i;
}
}
return -1;
}
function IniEvent() {
var tbl = document.getElementById("tblRating");
var tds = tbl.getElementsByTagName("td");
for (var i = 0; i < tds.length; i++) {
var td = tds[i];
td.onclick = tdOnClick;
td.style.cursor = "pointer"; //设置光标手型
}
}
function tdOnClick() {
var tbl = document.getElementById("tblRating");
var tds = tbl.getElementsByTagName("td");
//查找当前点击的td的索引
var index = ArrayIndexOf(tds, this);
//之前的td改为红色
for (var i = 0; i <= index; i++) {
tds[i].style.background = "red";
}
//之后的td改为白色
for (var i = index + 1; i < tds.length; i++) {
tds[i].style.background = "white";
}
}
</script>
</head>
<body onload="IniEvent()">
<table id="tblRating">
<tr>
<td>☆</td>
<td>☆</td>
<td>☆</td>
<td>☆</td>
<td>☆</td>
</tr>
</table>
</body>
</html>