扫描枪在页面上自动换行，

<html> 
<head> 
          <script   language= "javascript "> 
  function   keyEnter() 
  { 
          if   (event.keyCode   ==   13)   
  { 
                  event.keyCode   =   9; 
          }     
  } 
  document.onkeydown   =keyEnter; 
          </script> 
</head> 
<body> 
<form   name= "main "   action= "xx.htm ">       
<tr> 
        <td> <input   type= "text "   name= "text1 "> </td> 
      </tr> 
      <br/> 
      <tr> 
        <td> <input   type= "text "   name= "text2 "> </td> 
      </tr> 
      <br/> 
      <tr> 
            <td> <input   type= "button "   name= "submit1 "   value= "&Igrave;á&frac12;&raquo; "     onFocus= "   main.submit() "> </td> 
</tr> 
</form> 
    </body> 
</html> 

 就是将回车换成tab