求助啊，关于响应事件的问题！……

Question

<script>
function showhide()
{
document.all.c.style.display=document.all.myradio[0].checked?"block":"none";
}
</script>
<form action=next.jsp>
<input type=radio name=myradio value=a checked onclick=showhide()>show
<input type=radio name=myradio value=b onclick=showhide()>hide
<center>
<table id=c>
<tr><td><input id=mytext1></td></tr>
<tr><td><input id=mytext2></td></tr>
</table>
</center>

Answer 1

<script>
function showhide()
{
document.all.c.style.display=document.all.myradio[1].checked?"block":"none";
}
</script>
<form action=next.jsp>
<input type=radio name=myradio value=a onclick=showhide()>hide
<input type=radio name=myradio value=b checked onclick=showhide()>show
<center>
<table id=c>
<tr><td><input id=mytext1></td></tr>
<tr><td><input id=mytext2></td></tr>
</table>
</center>
<input type=submit value=submit>
</form>