Общие вопросы

<form onsubmit="return checkForm(this)">
<INPUT type=radio name="radio" value=Value1>Value1
<INPUT type=radio name="radio" value=Value2>Value2
<INPUT type=radio name="radio" value=Value3>Value3
<INPUT type=submit >
</form>

<script language=javascript>
function checkForm(frm){
for(i=0; i < frm.radio.length; i++){
if(frm.radio[i].checked){
alert("Выбрано: "+frm.radio[i].value);
return true; break;
}
}
alert("Ничего не выбрано!");
return false;
}
</script>