Bootstrap的边栏与固定页脚和可滚动div

正如你从下面的图片中看到的那样，我有可滚动的TreeView的侧边栏部分没有工作，我也需要固定页脚到这个侧边栏，当用户滚动侧边栏时它不会移动。如何解决它？

As you see from the picture below the part of sidebar where I have scrollable TreeView didnt work, also I need to have fixed footer to this sidebar that doesn't move when user scroll the sidebar. How to fix it?

我想要有下一个结构。

I want to have next structure.

.html

<div class="container-fluid max-height no-overflow">
        <div class ="row max-height">
            <form runat="server">
                    <!--SIDEBAR-->
                    <div class="col-sm-3 sidebar">

                        <div class="panel-body  scrollable">
                            TREEVIEW HERE
                        </div>

                        <div class="panel-footer center-block">
                            BUTTON HERE
                        </div>
                    </div>  

                <!--MAIN CONTENT-->
                <div class="col-sm-offset-3 main scrollable">
                    MAIN CONTENT HERE
                </div>
            </form>
         </div>
     </div>
</div>

css：

css:

        .scrollable {
            height: 100%;
            overflow: auto;
        }
        .max-height {
            height: 100%;

        }
        .no-overflow {
            overflow: hidden;
        }
        .sidebar {
            display: none;
        }
        @media (min-width: 768px) {
            .sidebar {
                position: fixed;
                bottom: 0;
                left: 0;
                z-index: 1000;
                display: block;
                overflow-x: auto;
                overflow-y: auto; /* Scrollable contents if viewport is shorter than content. */
                background-color: #f5f5f5;
            }
        }
        .main {
            padding-top: 20px;

        }
        @media (min-width: 768px) {
            .main {
                padding-right: 20px;
                padding-left: 20px;

            }
        }
        .panel-body{
            overflow: auto;
        }
        .panel-footer{
            background-color:#ff6a00;
        }