Vertical scrolling in div

Find simple code here to do vertical smooth scrolling in div

<script type="text/javascript">

        var InterVal;

        var divScroll;

        function ScrollUp(obj) {

            divScroll = document.getElementById(obj);

            InterVal = setInterval(StartUp, 50);

        }

     
       function ScrollDown(obj) {

            divScroll = document.getElementById(obj);

            InterVal = setInterval(StartDown, 50);

        }

        function StartUp() {

            divScroll.scrollTop -= 2;

        }

        function StartDown() {

            divScroll.scrollTop += 2;

        }

        function Stop(obj) {

            clearInterval(InterVal);

        }

        function Hide(DivMid, divup, divdown) {

            var divUp = document.getElementById(divup);

            var divDown = document.getElementById(divdown);

            DivMid.scrollTop >= 6 ? divUp.style.display = "block" :
                                                divUp.style.display = "none";

            DivMid.scrollHeight <= DivMid.clientHeight + DivMid.scrollTop ?
                                                        divDown.style.display = "none" :
                                                        divDown.style.display = "block";

        }      

    </script>

<div id="up" align="center" onmouseover="return ScrollUp('divScroll')"
        onmouseout="return  Stop('divScroll')"  style="width: 30%;
        background-color: #FFDEAD; display: none;"> UP</div>

 <div style="width: 30%; height: 100px; overflow: hidden;" id="divScroll"
         onscroll="Hide(this,'up','down');">

            Ajay <br />

            Patel <br />

            Patel <br />

            Ajay  <br />

            Rahul <br />

            Me    <br />

            Sam  <br />

            Pizza <br />

            Hut   <br />

            Like   <br />

            Ajay  <br />

            Rahul <br />

            Me    <br />

        </div>

        <div id="down" align="center" onmouseover="return ScrollDown('divScroll');"
               onmouseout="return Stop('divScroll');" style="width: 30%;

               background-color: #FFDEAD;">down</div>

 

         Result will like this :

Enjoy....................