select的readOnly

<select onbeforeactivate="return false" onfocus="this.blur()" onmouseover="this.setCapture()" onmouseout="this.releaseCapture()"> 
<option>1</option> 
<option selected>2</option> 
<option>3</option> 
</select>

  <select     onchange="selectedIndex=2">   
  <option   value=1>1</option>   
  <option   value=2>2</option>   
  <option   value=3   selected>3</option>   
  <option   value=4>4</option>   
  </select>   
  <input   type=checkbox   checked   onclick="checked=defaultChecked">   
  <input   type=radio   onclick="checked=defaultChecked">