Multiple Radio Button Field Form Validation

I'm only validating one (Consent) radio button with this code but I need to validate multiple different questions/buttons.

<script>
function getRBtnName(GrpName) {
var sel = document.getElementsByName(GrpName);
var fnd = -1;
var str = '';
for (var i=0; i<sel.length; i++) {
if (sel[i].checked == true) { str = sel[i].value; fnd = i; }
} return fnd;
}

function checkForm() {
var chosen = getRBtnName('Consent');
if (chosen < 0) {
alert( "Please choose one answer when you are asked to select a number." );
return false;
} else { return true; }
}

</script>
<form action="congratulations_aff.php" method="post" name="congratulations_aff" onSubmit="return checkForm()">
<table border="0" cellspacing="1" cellpadding="0">
<tr>
<td colspan="3">I consent to providing my electronic signature.</p></td>
</tr>
<tr>
<td colspan="3" valign="top">
<input type="radio" name="Consent" value="Y" />
Yes
<input type="radio" name="Consent" value="N" />
No

<table border="0" cellspacing="1" cellpadding="0">
<tr>
<td>I consent to electronic receipt of my information reporting documentation.</td>
</tr> <tr>
<td valign="top">
<input type="radio" name="Consent1099YesNo" value="Y" />
Yes
<input type="radio" name="Consent1099YesNo" value="N" />
No</td>
</tr>
<tr>
<td valign="top">

For tax purposes are you a U.S. citizen, U.S. resident, U.S. partnership, or U.S. corporation?
<input type="radio" name="USPersonYesNo" value="Y" /> Yes
<input type="radio" name="USPersonYesNo" value="N" /> No
</tr> </table>
<input type="submit" value="submit" value="Submit" />
</form>