Checkout Widget Template to add a checkbox to confirm a purchase

CustomCheckout.ascx

<%@ Control Language="C#" %>
<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
<%@ Register Assembly="Telerik.Sitefinity" Namespace="Telerik.Sitefinity.Modules.Ecommerce.Orders.Web.UI.CheckoutViews" TagPrefix="checkoutViews" %>


<h1 class="sfcheckoutTitle">
    <asp:Literal ID="checkoutTitle" runat="server" Text='<%$Resources:OrdersResources, Checkout %>' />
</h1>

<!-- This container is used to display warning messages about set up of the widget;
     when control is set correctly, this container is invisible -->
<div id="widgetStatus" runat="server" visible="false" class="sfErrorSummary">
    <asp:Label ID="widgetStatusMessage" runat="server" />
</div>

<asp:PlaceHolder id="widgetBody" runat="server">
    <telerik:RadTabStrip id="checkoutTabStrip" runat="server" Skin="Basic" CssClass="sfcheckoutTabstrip" EnableEmbeddedSkins="false" MultiPageID="checkoutMultiPage" SelectedIndex="0">
        <Tabs>
            <telerik:RadTab Text='<%$Resources:OrdersResources, Step1ShippingInformation %>' CssClass="sfStep1">
            </telerik:RadTab>
            <telerik:RadTab Text='<%$Resources:OrdersResources, Step2ShippingOptions %>' Enabled="false" CssClass="sfStep2">
            </telerik:RadTab>
            <telerik:RadTab Text='<%$Resources:OrdersResources, Step3Payment %>' Enabled="false" CssClass="sfStep3">
            </telerik:RadTab>
            <telerik:RadTab Text='<%$Resources:OrdersResources, Step4Preview %>' Enabled="false" CssClass="sfStep4">
            </telerik:RadTab>
            <telerik:RadTab Text='<%$Resources:OrdersResources, Step5Confirmation %>' Enabled="false" CssClass="sfStep5">
            </telerik:RadTab>
        </Tabs>
    </telerik:RadTabStrip>

    <telerik:RadMultiPage id="checkoutMultiPage" runat="server" SelectedIndex="0" RenderSelectedPageOnly="true" CssClass="sfcheckoutMulitPage">
        <telerik:RadPageView id="shippingInformationPageView" runat="server" CssClass="sfStep1Wrp">
            <checkoutViews:ShippingAndBillingInformation id="shippingAndBillingInformation" runat="server" />
        </telerik:RadPageView>
        <telerik:RadPageview id="shippingOptionsView" runat="server" CssClass="sfStep2Wrp">
            <checkoutViews:ShippingOptions id="shippingOptions" runat="server" />
        </telerik:RadPageview>
        <telerik:RadPageView id="paymentView" runat="server" CssClass="sfStep3Wrp">
            <checkoutViews:PaymentStep id="paymentStep" runat="server" />
        </telerik:RadPageView>
        <telerik:RadPageView id="previewView" runat="server" CssClass="sfStep4Wrp">
            <input type="checkbox" id="chkAcceptTermsAndConditions" /> <label for="chkAcceptTermsAndConditions"><strong>Click to accept our terms and conditions to place the order</strong></label>
            <checkoutViews:Preview id="preview" runat="server" />
        </telerik:RadPageView>
        <telerik:RadPageView id="confirmationView" runat="server" CssClass="sfStep5Wrp">
            <checkoutViews:Confirmation id="confirmation" runat="server" />
        </telerik:RadPageView>
    </telerik:RadMultiPage>
</asp:PlaceHolder>

<script type="text/javascript">
    $(document).ready(function () {
        $('.sfStep4Wrp .sfcheckoutBtnsWrp .sfcheckoutContinueBtn').attr('disabled', 'disabled');

        $('#chkAcceptTermsAndConditions').click(function () {
            if (this.checked) {
                $('.sfStep4Wrp .sfcheckoutBtnsWrp .sfcheckoutContinueBtn').removeAttr('disabled');        
            }
            else {
                $('.sfStep4Wrp .sfcheckoutBtnsWrp .sfcheckoutContinueBtn').attr('disabled', 'disabled');
            }

        });
    });

</script>