JQuery ListBox间移动和ListBox内上下移动

var $btnUp = $("#ChooseUserControl1_btnUp");
            var $btnDown = $("#ChooseUserControl1_btnDown");
//选择的联系人上下移动///////////////////////////////////
            $btnUp.click(function()
            {
                $lbSelLinkMan.find("option:selected").each(function(index, item)
                {        
                    ListBox_Order("up");
                });
return false;
            });
            $btnDown.click(function()
            {
                $lbSelLinkMan.find("option:selected").each(function(index, item)
                {
                    ListBox_Order("down");
                });
return false;
            });
            function ListBox_Order(action)
            {               
                var size = $lbSelLinkMan.find("option").size();
                var selsize = $lbSelLinkMan.find("option:selected").size();
if (size > 0 && selsize > 0)
                {                   
                    $lbSelLinkMan.find("option:selected").each(function(index, item)
                    {
if (action == "up")
                        {
                            $(item).prev().insertAfter($(item));
return false;
                        }
else if (action == "down")//down时选中多个连靠则操作没效果
                        {
                            $(item).next().insertBefore($(item));
return false;
                        }
                    })
                }
return false;
            }