javascript实现全选，反选及全不选(其一)

javascript实现全选，反选及全部选

html 代码：

<!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=gb2312" />
<title>无标题文档</title>
<script language="javascript">
function select1(oper){
var arr= document.getElementsByName("fav");
for(var i=0;i<arr.length;i++){
switch(oper){
case 1:
arr[i].checked=oper;
break;
case 0:
arr[i].checked=oper;
break;
case -1:
arr[i].checked=! arr[i].checked;
break;
}
}
}
</script>
</head>
<body>
<input type="checkbox" name="fav"  value="吃饭"/>吃放
<input type="checkbox" name="fav"  value="吃饭2"/>吃放2
<input type="checkbox" name="fav"  value="吃饭3"/>吃放3
<input type="checkbox" name="fav"  value="吃饭4"/>吃放5
<input type="checkbox" name="fav"  value="吃饭6"/>吃放6
<input type="checkbox" name="fav"  value="吃饭7"/>吃放7
<input type="checkbox" name="fav"  value="吃饭8"/>吃放8
<input type="button" value="全选"  onclick="select1(1)" />
<input type="button" value="反选"  onclick="select1(-1)" />
<input type="button" value="取消"  onclick="select1(0)" />
</body>
</html>