Try this as the complete script:
<script type="text/javascript" charset="utf-8">
$(document).ready(function() {
var qID = 2326;
$('#question'+qID+' table.question tbody td').click(function () {
var cellClass = $(this).attr('class');
var parent = $(this).parent();
setTimeout(function() {
if($('.'+cellClass+' input[type=radio]:checked').length > 1) {
$('.'+cellClass+' input[type=radio]').attr('checked', false);
$('.'+cellClass+' input[type=radio]', parent).attr('checked', true);
}
}, 250);
});
// Interrupt the submit function and check each column for a checked radio
$('form#limesurvey').submit(function(){
var warningText = 'Please answer 3 to continue';
var ok = 1;
$('#question'+qID+' table.question tbody:first td').each(function(i) {
var colClass = $(this).attr('class');
if($('.'+colClass+' input.radio:checked').length < 1) {
ok = 0;
}
});
if(ok == 0) {
alert (warningText);
return false;
}
else {
return true;
}
});
});
</script>