Hurtigt skiftning

Kode 

<form action="post.php" method="post" name='send'>
<table width="473" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td width="8%"> Navn: </td>
    <td width="38%"><input name="navn" id="navn" type="text" onkeydown="if(!event) var event = window.event; var key = event.keyCode? event.keyCode: e.which; if(key == 40) { var obj = document.getElementById('efternavn'); obj.focus(); obj.select(); }" /></td>
    <td width="24%">Efternavn:</td>
    <td width="30%"><input name="efternavn" type="text" id="efternavn" onkeydown="if(!event) var event = window.event; var key = event.keyCode? event.keyCode: e.which; if(key == 40) { var obj = document.getElementById('alder'); obj.focus(); obj.select(); } else if(key == 38) { var obj = document.getElementById('navn'); obj.focus(); obj.select(); }" /></td>
  </tr>
  <tr>
    <td>Alder</td>
    <td><input name="alder" type="text" id="alder" onkeydown="if(!event) var event = window.event; var key = event.keyCode? event.keyCode: e.which; if(key == 40) { var obj = document.getElementById('fodt_d'); obj.focus(); obj.select(); } else if(key == 38) { var obj = document.getElementById('efternavn'); obj.focus(); obj.select(); }" /></td>
    <td>født d. </td>
    <td><input name="fodt_d" type="text" id="fodt_d" onkeydown="if(!event) var event = window.event; var key = event.keyCode? event.keyCode: e.which; if(key == 38) { var obj = document.getElementById('alder'); obj.focus(); obj.select(); }" /></td>
  </tr>
  <tr>
    <td> </td>
    <td colspan="3"><input name="send" type="submit" value="Send" /></td>
  </tr>
</table>
</form>