利用CSS控制SELECT中的OPTION是否不允许选

<meta http-equiv="Content-Type" content="text/html;charset=UTF-8"> <style type="text/css"> .disabled { } .disabled optgroup{ font-size: 12px; font-style: normal; font-weight: normal; font-variant: normal; color:#cccccc; background-color: #f5f5f5; } .disabled option { padding-left:0px; } </style> <title></title> <select name="carcos" class="disabled"><optgroup label="american"></optgroup> <option value="general motors">general motors </option> <option value="ford">ford motor company </option> <option value="chrysler">daimlerchrysler </option> <optgroup label="japanese"></optgroup></select> 用这种变态的方式可以实现，在firefox和ie6下看效果很好
[ctrl+a 全选 注:如需引入外部js需刷新才能执行]