How to separate an array of checkboxes into groups

[SilverNightFall]

How would I alert the user if they selected more than one COP1000 and in another instance alert the user if they selected more than one COP 2830. Right now it notifies the user if they selected more than one class.

<script type="text/javascript" charset="utf-8">
var p = 0;
$(document).ready(function () {
    $('input:checkbox').click(function () {
        var COP1000 = $(this).attr('data');
        if ($('input:checkbox:is_checked').attr()) {
            p++;
        }
        if (p >= 2) {
            alert('You can only select this class once');
            return false;
        }
    });
});
</script>

Below are checkboxes with data being the name of the class

<input name="class[]" data="COP1000" value="<tr><td>COP1000 <td>8:00AM-9:00AM 
</td><td>MWF </td><td>Sanford </td><td>3</td></tr>" type="checkbox" class="auto-
style88"/>
<input name="class[]" data="COP1000" value="<tr><td>COP1000 <td>11:30AM-12:00PM
</td><td>TTH </td><td>Altamonte </td><td>3</td></tr>" type="checkbox" class="auto-
style88" />

<input name="class[]" data="COP2830" value="<tr><td>COP2830 <td>11:00AM-12:00PM 
</td><td>MWF </td><td>Sanford </td><td>3</td></tr>" type="checkbox" class="auto-
style88"/>
<input name="class[]" data="COP2830" value="<tr><td>COP2830 <td>6:00PM-8:45PM 
</td><td>T </td><td>Altamonte </td><td>3</td></tr>" type="checkbox" class="auto-
style88"/>

[Dormilich]

make it a radio button with a single name for each group that should be unique.

note: HTML code (i.e. the < and > of the HTML tags) are not allowed as attribute value.