kendo窗口内的按钮未显示

Question

我的kendo窗口中有几个按钮，它们没有显示。

    <div id ="addDetails">
    <div id="details-container">
        <select id="details" />
        <br /> <br /> <br />
        <button class="k-button" id="submit">Insert</button>
        <button class="k-button" id="cancel">Cancel</button>
    </div>
</div>

在javascript下方调用以打开窗口，但按钮不会出现在div中。

$("#addDetails").kendoWindow({
    actions: ["Custom", "Pin", "Refresh", "Maximize", "Minimize", "Close"],
    draggable: false,
    height: "300px",
    modal: true,
    pinned: false,
    position: {
        top: 100,
        left: 100
    },
    resizable: false,
    title: "Add Details",
    width: "500px"
});
var wnd = $("#addDetails").data("kendoWindow");
displayDetails();

wnd.center().open();