设置相等的
name属性以创建组；
<form> <fieldset id="group1"> <input type="radio" value="value1" name="group1"> <input type="radio" value="value2" name="group1"> </fieldset> <fieldset id="group2"> <input type="radio" value="value1" name="group2"> <input type="radio" value="value2" name="group2"> <input type="radio" value="value3" name="group2"> </fieldset></form>
