js 实现对Select动态赋值 C#从后台获取

<script type="text/javascript">
$(function () {

var Annuals = $("#txtAnnual");
var today = new Date();
var year = today.getFullYear();
Annuals.empty();
for(var i=year-1;i<=year+1;i++)
{
var option = $("<option>").text(i+'年').val(i)
Annuals.append(option);
}

})
</script>

<select id="txtAnnual" name="txtAnnual" runat="server">
<option></option>
</select>

string year = Request["txtAnnual"];