java script

Hey there, so i’m not sure if this is where i need to be posting – sorry if this is the wrong location/etiquette. Also i am a pretty big newbie!

So, I have a page where my clients put in their payment details into a form. When the form is submitted, the details are then submitted into the payment gateway. My issue is this: I need to automatically add a 1.5% surcharge to what ever figure is added by the user, to cover the credit card costs before it goes to the payment gateway. I have worked out how to do this using javascript, but cant get this to work on the wordpress site.

The form code and the js is below. I have used the plugin ‘code embed’ but unfortunately it is still not working for me. Any help/suggestions would be much appreciated. Alternatively, if there is a much better way of going about it I am all ears.

<form action="" method="post">
    <table>
        <tbody>
            <tr>
                <td>Your Name:</td>
                <td>
                    <input maxlength="64" name="TxnData1" id="name" type="text" value="" />
                </td>
            </tr>
            <tr>
                <td>Your Email:</td>
                <td>
                    <input name="EmailAddress" id="email" type="text" value="" />
                </td>
            </tr>
            <tr>
                <td>Quote/Invoice Reference No:</td>
                <td>
                    <input name="MerchantReference" id="quote" type="text" value="" />
                </td>
            </tr>
            <tr>
                <td>Amount:</td>
                <td>
                    <input name="Amount" id="Amount" type="text" value="00.00" />
                </td>
            </tr>
            <td>Amount with surcharge:</td>
            <td><span id="AmountInput"></span>

            </td>
            </tr>
            <!-- Indicate what currency the transaction will be in -->
            <tr>
                <td>Currency:</td>
                <td>Australian Dollar(AUD)</td>
            </tr>
            <tr>
                <td></td>
                <td>
                    <input name="mypaymentform" type="submit" value="Next" />
                </td>
            </tr>
        </tbody>
    </table>
</form>

js

<script type="text/javascript"> $(document).ready(function () {
    $('#Amount').keyup(function () {
        $('#AmountInput').text($('#Amount').val() * 1.15);
    });
});</script>

thank you in advance, and et me know if you need any more info!

Thanks