可写可选dropdownlist(只测试过ie)

 页面：

报废申请人：<asp:TextBox ID="txtPUSER" runat="server" Width="70px" CssClass="txt"></asp:TextBox>  
                    <div style="display:none ;width:95px;z-index:1000;position:absolute;background-color:#33CCCC; height:200px;overflow:scroll;" id="DivApplyPerson">
                    </div> 

相应的js：

function getUserList() {

        var top = $('#txtPUSER').offset().top;
        top += 20;
        var left = $('#txtPUSER').offset().left;
        var name = $('#txtPUSER').val();
        var ksListAll = null;
        $.ajax({
            type: "post",
            async: false,
            dataType: 'json',
            url: '../Ajax/Locker.ashx',
            data: { active: "getUser", Name: escape(name) },
            success: function(json) {
                ksListAll = json.list;
            }
        });
        $('#DivApplyPerson').css("top", top);
        $('#DivApplyPerson').css("left", left);
        $('#DivApplyPerson').css("display", "block");
        var strHTML = "";
        if (ksListAll != null) {
            $.each(ksListAll, function(i, item) {
                strHTML = strHTML + "<a href='#' onclick='getVal(this)' value='" + item.DEPTID + "' style=' width:100px; float:left'>" + item.FULLNAME + "</a>"
            });
        }
        $("#DivApplyPerson").html(strHTML);

    }

    $('#txtPUSER').focus(function() {

        getUserList();

    }).keyup(function() {
        getUserList();

    });
    function getVal(a) {
        $("#txtPUSER").val(a.innerText);
        $('#DivApplyPerson').css("display", "none");
    }
    $("#txtPUSER").blur(function() {
        if (document.activeElement.parentElement != null) {
            if (document.activeElement.parentElement.id != "DivApplyPerson") {
                $('#DivApplyPerson').css("display", "none");
            }
        }
    });