透过document.getElementsById来实现 复选框的全选，全部选，反选
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>
<body>
<table width="300" cellspacing="0" cellpadding="0">
<tr>
<td><input type="checkbox" id="chec1" /></td>
<td>发票</td>
<td>2013-02-12</td>
</tr>
<tr>
<td><input type="checkbox" id="chec2" /></td>
<td>旅馆</td>
<td>2013-02-13</td>
</tr>
<tr>
<td><input type="checkbox" id="chec3" /></td>
<td>乞讨</td>
<td>2013-02-14</td>
</tr>
<tr>
<td><input type="button" value="全选" onclick="selectALL()" /></td>
<td><input type="button" value="全不选" onclick="selectNO()" /></td>
<td><input type="button" value="反选" onclick="reverse()" /></td>
</tr>
</table>
</body>
<script type="text/javascript">
function selectALL(){//全选
var trs = document.getElementsByName('tr');
for(var i=1;i<trs.length;i++){
document.getElementById("chec"+i).checked=true;}
}
function selectNO(){//全不选
for(var i=1;i<=3;i++){
document.getElementById("chec"+i).checked=false;}
}
function reverse(){//反选
for(var i=1;i<=3;i++){
if(document.getElementById("chec"+i).checked==true){
document.getElementById("chec"+i).checked=false;
}else{
document.getElementById("chec"+i).checked=true; }}
}
</script>
</html>