{source}
<!-- You can place html anywhere within the source tags -->
<form id="form1" action="results-action" method="post" name="form1">
<div>
<p><input id="school" name="school" type="checkbox" group="group1" value="1" />I am a school or other organization would like to schedule an online or in person presentation</p>
<p><input id="age" name="age" type="checkbox" group="group1" value="1" />I am a student under the age of 18</p>
<p><input id="ownership" name="ownership" type="checkbox" group="group1" value="1" />I would like to learn more about owning my own online apparel store and becoming an entrepreneur</p>
</div>
<div>
<p><input id="coach" type="checkbox" name="coach" group="group1" value="1" />I am interested in one on one coaching to become a store owner and entrepreneur</p>
<p><input id="teacher" type="checkbox" name="teacher" group="group1" value="1" /> I am a teacher or adult and would like to volunteer to teach and mentor kids</p>
</div>
<input id="submit" type="submit" group="submit" value="Submit" disabled/>
</form>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

<script language="javascript" type="text/javascript">
    // You can place JavaScript like this
    jQuery("input:checkbox").on('click', function() {
    // in the handler, 'this' refers to the box clicked on
    var box = jQuery(this);
    if (box.is(":checked")) {
    // the name of the box is retrieved using the .attr() method
    // as it is assumed and expected to be immutable
    var group = "input:checkbox[group='" + box.attr("group") + "']";
    // the checked state of the group/box on the other hand will change
    // and the current value is retrieved using .prop() method
    jQuery(group).prop("checked", false);
    jQuery("#submit").prop('disabled', false);
    box.prop("checked", true);
    } else {
    box.prop("checked", false);
    jQuery("#submit").prop('disabled', true);
    }
});

    
</script>
<?php
    // You can place PHP like this
    
?>
{/source}