This is my first post on this site so hopefully you will go easy on me. I'm trying to create an HTML / PHP form and use a small piece of Javascript to add additional rows to a table when a button is clicked and increment the ID for the two fields. 

The button works in adding the rows however it doesn't seem to increment the ID, just use the same ID as the previous row. Hopefully someone could help?

```js
$(window).load(function(){
        var table = $('#productanddates')[0];

    var newIDSuffix = 2;
    $(table).delegate('#button2', 'click', function () {
        var thisRow = $(this).closest('tr')[0];

        var cloned = $(thisRow).clone();
        cloned.find('input, select').each(function () {
            var id = $(this).attr('id');
            id = id.substring(0, id.length - 1) + newIDSuffix;
            $(this).attr('id', id);
        });

        cloned.insertAfter(thisRow).find('input:date').val('');

        newIDSuffix++;
    });
});  
```

```html
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div class="blue-bar ta-l">
    <div class="container">
        <h1>Submit Your Insurance Renewal Date(s)</h1>
    </div>
</div>
<div class="grey-bar">
    <div class="container">
        <div class="rounded-box">
            <div>
                <label for="name">Name</label>
                <input type="text" id="name" name="name" autocomplete="off" required />
            </div>
            <div>
                <label for="name">Renewal Dates</label>
            </div>
            <table width="100%" border="0" cellspacing="0" cellpadding="5" id="productanddates" class="border">
                    <tr>
                        <td>
                            <select name="insurance_type1" id="insurance_type1">
                                <option></option>
                                <option>Car</option>
                                <option>Home</option>
                                <option>Van</option>
                                <option>Business</option>
                                <option>GAP</option>
                                <option>Travel</option>
                            </select>
                        </td>
                        <td>
                            <input type="date" name="renewal_date1" id="renewal_date1" />
                        </td>
                        <td>
                            <input type="button" name="button2" id="button2" value="+" />
                        </td>
                    </tr>
            </table>
            <div>
                <label for="telephone_number">Contact Number</label>
                <input type="tel" id="telephone_number" name="telephone_number" pattern="\d{11}" autocomplete="off" required />
            </div>
            <div>
                <label for="email">Email Address</label>
                <input type="email" id="email" name="email" autocomplete="off" required />
            </div>
            <div>
                <input name="submit" type="submit" value="Submit" class="btn">
            </div>
        </div>
```