如何在校验控件数据后，使该控件得到焦点。

<Script>
function checkit(e)                                                   
 {                                            
   e.value=" ";
   e.focus();
   return false;                                                     
 }             
</Script>
<input name= 'T2' type='text'  size='15'  onblur='checkit(this)'>