$(document).ready(function() {

   $(".select").on('click',function() {

            $('html, body').animate({

            scrollTop: 100

        }, 100);

       setTimeout(function (){ openSelect($(".select"));

                              openSelect($(".select"));

                             },100)

         return false;

    });

});

function openSelect(obj)

    {

​

    var element = obj[0];

    if (document.createEvent)

    { // all browsers

    var e = document.createEvent("MouseEvents");

    e.initMouseEvent("mousedown", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);

    element.dispatchEvent(e);

    } else

    if (element.fireEvent)

    { // ie

    element.fireEvent("onmousedown");

    }

    }