单选按钮和标签组合点击

1、问题背景

现在，有个问题：一组单选按钮，点击按钮可以选中，但是点击标签label不能被选中。

2、实现源码

（1）点击按钮选中

<!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>单选按钮和标签组合点击</title>
<script type="text/javascript" src="jquery-1.12.3.js"></script>
<script type="text/javascript">

</script>
</head>

<body>
   <div>
      <input type="radio" id="man" name="sex" style="cursor:pointer"/>
      <label style="cursor:pointer">男</label>
      <input type="radio" id="woman" name="sex" style="cursor:pointer"/>
      <label style="cursor:pointer">女</label>
   </div>
</body>
</html>

（2）点击label选中

<!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>单选按钮和标签组合点击</title>
<script type="text/javascript" src="jquery-1.12.3.js"></script>
<script type="text/javascript">

</script>
</head>

<body>
   <div>
      <input type="radio" id="man" name="sex" style="cursor:pointer"/>
      <label style="cursor:pointer" for="man">男</label>
      <input type="radio" id="woman" name="sex" style="cursor:pointer"/>
      <label style="cursor:pointer" for="woman">女</label>
   </div>
</body>
</html>

（3）点击label选中

<!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>单选按钮和标签组合点击</title>
<script type="text/javascript" src="jquery-1.12.3.js"></script>
<script type="text/javascript">

</script>
</head>

<body>
   <div>
      <label style="cursor:pointer"><input type="radio" id="man" name="sex" style="cursor:pointer"/>
      男</label>
      <label style="cursor:pointer"><input type="radio" id="woman" name="sex" style="cursor:pointer"/>
      女</label>
   </div>
</body>
</html>

3、实现结果

（1）点击按钮选中

（2）点击按钮和label选中

（3）点击按钮和label选中