jQuery表单对象属性过滤选择器
<div id="p1" attr="p1">
<input type="text" id="in001" value="in001">
<input type="text" id="in002" disabled="disabled" value="in002">
<input type="checkbox" id="chk001" checked="checked" >
<input type="checkbox" id="chk002" >
<select id="slt001">
<option>11</option>
</select>
<select id="slt002" multiple="multiple" size="5" >
<option>21</option>
<option selected="selected">22</option>
<option>23</option>
<option selected="selected">24</option>
<option>25</option>
</select>
</div>
注意$(':checked')与$('input:checked')的区别;