这人意思吧:
<form onsubmit="return chk()">
<fieldset><legend>选择配送方式: </legend>
<div id="radios"><input type="radio" name="fput" value="快递">快递  <input type="radio" name="fput" value="EMS">EMS  <input type="radio" name="fput" value="邮寄">邮寄</div>
<br />
<input type="submit" name="sbumit">
</fieldset>
</form>
<script>
function chk(){
var rs = document.getElementById('radios').getElementsByTagName('input');
for(var i=0; i<rs.length; i++) if(rs[i].checked) return true;
return false;
}
</script>
<form onsubmit="return chk()">
<fieldset><legend>选择配送方式: </legend>
<div id="radios"><input type="radio" name="fput" value="快递">快递  <input type="radio" name="fput" value="EMS">EMS  <input type="radio" name="fput" value="邮寄">邮寄</div>
<br />
<input type="submit" name="sbumit">
</fieldset>
</form>
<script>
function chk(){
var rs = document.getElementById('radios').getElementsByTagName('input');
for(var i=0; i<rs.length; i++) if(rs[i].checked) return true;
return false;
}
</script>
<td>选择配送方式: </td>
<td> <input type="radio" name="fput" value="快递">快递  <input type="radio" name="fput" value="EMS">EMS  <input type="radio" name="fput" value="邮寄">邮寄 </td> </tr> <INPUT TYPE="button" value="Next" onclick="check()">
<SCRIPT LANGUAGE="JavaScript">
<!--
function check(){
var num = 0;
var oRadio = document.getElementsByName("fput");
for(var i=0;i<oRadio.length;i++){
if(oRadio[i].checked == true){
num+=1;
}
}
if(num>0)
alert('ok')
else
alert('error');
}
//-->
</SCRIPT>
OBJ=document.getElementsByName("fput")
for(var i=0;i<OBJ.length;i++){
if(OBJ[i].checked){
flag=true
}
}
if(!flag){
alert('请选择')
return false;
}