How to get selected index of a Html select in asp.net?
<p>I have code below:</p>

<pre><code> &lt;select id="test"&gt;
        &lt;option value="a"&gt;aaa&lt;/option&gt;
        &lt;option value="b"&gt;bbb&lt;/option&gt;
    &lt;/select&gt;
    &lt;asp:Button ID="btnTest" runat="server" Text="Test it!" onclick="btnTest_Click" /&gt;

I need to get selected index not selected value on postback. How can I do this with asp.net?

this is my code for filling the select html:
&lt;script language="javascript" type="text/javascript"&gt;
    $(document).ready(function() {
    $("#&lt;%=btnTest.ClientID %&gt;").click(function(){
    $.ajax(
    { url: "StateCity.asmx/ReferItems?id=" + getParameterByName('id'),
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        type: "POST",
        success: function(data) {
        $("#test").empty();
        $.each(data.d, function() {
        $("#test").append($("&lt;option&gt;&lt;/option&gt;").val(this['Value']).html(this['Text']));
        });

        },
        error: function() { alert("Error"); }
    }) 
    })
&lt;/script&gt;
</code></pre>
