javascript.js

    var historyCount  = parseInt($('#historyCount').val());

    $('#AddMaintenance').click(function(event) { event.preventDefault();
        var firstMaintenance = parseInt($('#FreezerFirstMaintenance').val());
        $('#preventativeMaintenance').clone(false, false).html($('#preventativeMaintenance').html()).find(':input').each(function() {
            $(this).attr('id', $(this).attr('id').replace(firstMaintenance, historyCount));
            $(this).attr('name', $(this).attr('name').replace('[' + firstMaintenance + ']', '[' + (historyCount) + ']'));
            if($(this).is('[type!="hidden"]')) { $(this).val(''); }
        }).end().insertBefore('#AddMaintenance'); historyCount++;
    });

php.php

        <fieldset style="border: none;">
            <legend id="preventativeMaintenanceLegend">
                <span class="ui-icon ui-icon-triangle-1-e" id="preventativeMaintenanceArrow" style="display: inline-block;"></span>
                <span>Preventative Maintenance Information</span>
            </legend>
            <div id="preventativeMaintenances" style="display: none; margin-left: 2.5%;">
                <div id="preventativeMaintenance">
                    <?php
                    /* THIS IS THE IMPORTANT PART:
                       You need a hidden field that keeps track of whatever your first hard-coded form is.
                       In the above JS, you need the var firstMaintenance = stuff to be named the same.
                    */
                    echo $this->Form->hidden('firstMaintenance', array('value' => 0));
                    echo $this->Form->hidden('EquipmentHistory.0.subject', array('value' => '1'));
                    echo $this->Form->input('EquipmentHistory.0.date', array('empty' => true));
                    echo $this->Form->input('EquipmentHistory.0.details');
                    ?>
                </div>
            <?php for($i = 4; $i < count($this->data['EquipmentHistory']); $i++): ?>
                <?php if($this->data['EquipmentHistory'][$i]['subject'] == 1): ?>
                <div id="preventativeMaintenance">
                    <?php
                    echo $this->Form->hidden('EquipmentHistory.' . $i . '.subject', array('value' => '1'));
                    echo $this->Form->input('EquipmentHistory.' . $i . '.date', array('empty' => true));
                    echo $this->Form->input('EquipmentHistory.' . $i . '.details');
                    ?>
                </div>
                <?php endif; ?>
            <?php endfor; ?>
                <button id="AddMaintenance">Add Preventative Maintenance Information</button>
            </div>
        </fieldset>