<asp:ListBox ID="ListUsers" runat="server" Height="313px" SelectionMode="Multiple" Width="185px" ></asp:ListBox>

  <asp:ListBox ID="ListSelectedUsers" runat="server" Height="313px"  SelectionMode="Multiple" Width="199px" "></asp:ListBox>

  <asp:TextBox ID="SelectedMode" runat="server" Style="display: none"></asp:TextBox>

 function SelectOne() {

            var lst1 = window.document.getElementById("ListUsers");

            var lstindex = lst1.selectedIndex;

            if (lstindex < )

                return;

            var v = lst1.options[lstindex].value;

            var t = lst1.options[lstindex].text;

            var lst2 = window.document.getElementById("ListSelectedUsers");

            var mode = window.document.getElementById("SelectedMode");

            if (mode.value == "True") { //如果是单值，先删除所有

                for (var i = lst2.options.length - ; i >= ; i--) {

                    lst2.remove(i);

                }

                lst2.add(new Option(t, v, true, true), );

            } else{

                var isExists = false;

                for (var i = ; i < lst2.options.length; i++) {

                    if (lst2.options[i].value == v) { //防止添加重复项

                        isExists = true;

                        break;

                    }

                }

                if (!isExists) {

                    lst2.options[lst2.options.length] = new Option(t, v, true, true);

                }

            }

        }

        //选择一条数据删除

        function DelOne() {

            var lst = window.document.getElementById("ListSelectedUsers");

            var lstindex = lst.selectedIndex;

            if (lstindex >= ) {

                var v = lst.options[lstindex].value + ";";

                lst.options[lstindex].parentNode.removeChild(lst.options[lstindex]);

            }

        }

if (!IsPostBack)

 {

    ListBoxBand();

    SelectedMode.Text = "True";

    ListUsers.Attributes.Add("onDblClick", "SelectOne()");//双击事件    
    ListSelectedUsers.Attributes.Add("onDblClick", "DelOne()");//双击事件

}

 private void ListBoxBand()

{ 

    for (int i = ; i < ; i++)

    {

　　    ListUsers.Items.Add(new ListItem("Index" + i, i.ToString()));

    }

}