select表單添加可選與不可選的表單項代碼

<select name="" id="">
<option value="">請選擇</option>
<optgroup label="标題1" title="">
<option value="" title="">選項1-1</option>
<option value="" title="">選項2-2</option>
</optgroup>
<optgroup label="标題2" title="">
<option value="armscii8_bin" title="">選項2-1</option>
<option value="armscii8_general_ci" title="">選項2-1</option>
</optgroup>
</select>