Changing Checkbox to Radio Buttons

Hi there,

I have some code which allows checkboxes to be selected in an array of found records. I want to change this to a set of 3 radio buttons called Yes, No and Unknown but cant work out how to modify the code:

Here's the code:

if ($_POST['proposal']) {

foreach ($_POST['proposal'] as $key => $value) {

$update = new FX($serverIP,$webCompanionPort,'FMPro7');

$update -> SetDBData('Training Calendar.fp7','Presenter_and_Course');

$update -> SetDBPassword('fmsadmin','fmsadmin');

$update -> AddDBParam('-recid', $key);

$update -> AddDBParam('Run_Again', 'Yes'); //I think this needs to be modified somehow as there are 3 possible results in the radio buttons - Yes, No and Unknown

$update -> FMEdit();

and further down:

<?php

$Courses=new FX($serverIP,$webCompanionPort,'FMPro7');

$Courses->SetDBData('Training Calendar.fp7','Presenter_and_Course');

$Courses->SetDBPassword('fmsadmin','fmsadmin');

$Courses->AddDBParam('Presenter_ID', $UN_CheckData['Presenter_ID'][0], 'eq');

$Courses->AddSortParam('Course_Name','ascend');

$CoursesResult=$Courses->FMFind();

$returnedCount=$CoursesResult['foundCount'];

foreach($CoursesResult['data'] as $key=>$CoursesData){ $recid = explode('.', $key); ?>

and the checkbox itself:

This is the proposed radio button code:

Any assistance gratefully received.