How to display different input type depending on s

I am developing an web application with vb.net and asp.net.

In this web application one of the web form is like below New status (required)

the options/data shown in the above drop-down list is coming from data base and they are conditional as well. these options are not fixed all the time. they are visible depending on a previous selection by the user.

Among those data there are 3 data for which I want to display 3 different input types. the id of these 3 option/data are 10, 11 and 12.

I want to display different input type below this drop-down list depending on the selected data in the drop-down list.

Example

If in the drop down list the selected data id is 10 I want to display a text box below the dropdown list

            <div class="form-element">
               <label>Offered salary (numeric only!!)</label>
                <input type="text" id="txtOfferedSalary" class="txtOfferedSalary" runat="server" data-bind="value:offeredSalary, valueUpdate: 'afterkeydown'" />
            </div>

If in the drop down list the selected data id is 12 I want to display a calender below the dropdown list

               <div class="form-element">
                <label>
                    Start date (required if job offered, format: DD-MMM-YYYY)
                </label>
                <div class="input-append">
                    <span class="add-on "><span class="icon-calendar"></span></span>
                    <input class="dp" size="16" type="text" value="" runat="server" id="txtStartDate" />
                </div>
            </div>

For the rest of the data I dont want to do anything. How can I do it with javascript? Please help me with code.

Thank you

Edited code

<%@ Page Title="" Language="VB" MasterPageFile="~/_resx/E4_Popup.master" AutoEventWireup="false" CodeFile="update-status_popup.aspx.vb" Inherits="E4_Jobs_Details_Application_update_status" %>


<asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="Server">

            <div class="form-element">
                <label>New status (required)</label>
                <select id="comNewStatus" runat="server" datavaluefield="id" datatextfield="name" class="nFee" onchange="displayDiv()"></select>
            </div>


               <div id="cal" class="form-element">
                <label>
                    Start date (required if job offered, format: DD-MMM-YYYY)
                </label>
                <div class="input-append">
                    <span class="add-on "><span class="icon-calendar"></span></span>
                    <input class="dp" size="16" type="text" value="" runat="server" id="txtStartDate" />
                </div>
            </div>

</asp:Content>



<asp:Content ID="Content2" ContentPlaceHolderID="ScriptContent" runat="Server">
     <script type="text/javascript">

      function displayDiv() {
          if ($("#comNewStatus").val() == "1") {
              $("#cal").show();
          }
          else {
              $("#cal").hide();
          }
      }

     function RefreshParent() {
         if (window.opener != null && !window.opener.closed) {
             window.opener.location.reload();
              }
         }
   window.onbeforeunload = RefreshParent;


</script>

  </asp:Content>

all the references of jquery and ko-js have been made in the master file.

Add jquery and add Id's to your divs, hide them by default (display:none) and then display them on the onchange event of the select control.

Edit: added proper control id resolving in case of master/detail pages.

<head runat="server">
    <title></title>
    <script src="Scripts/jquery-1.8.2.min.js" type="text/javascript"></script>
    <script type="text/javascript">
        function displayDiv() {
            if ($("#<%= comNewStatus.ClientID %>").val() == "2") {
                $("#divFirst").show();
            }
            else {
                $("#divFirst").hide();
            }
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <div class="form-element">
            <label>
                New status (required)</label>
            <select id="comNewStatus" runat="server" datavaluefield="id" datatextfield="name"
                class="nFee" onchange="displayDiv()">
                <option value="1">Option 1</option>
                <option value="2">Option 2</option>
                <option value="3">Opotion 3</option>
            </select>
        </div>
    </div>
    <div id="divFirst" class="form-element" style="display:none;">
        <label>
            Offered salary (numeric only!!)</label>
        <input type="text" id="txtOfferedSalary" class="txtOfferedSalary" runat="server"
            data-bind="value:offeredSalary, valueUpdate: 'afterkeydown'" />
    </div>
    <div id="divSecond" class="form-element" style="display:none;">
        <label>
            Final salary (numeric only!!)</label>
        <input type="text" id="txtFinalSalary" class="txtFinalSalary" runat="server" data-bind="value:finalSalary, valueUpdate: 'afterkeydown'" />
    </div>
    </form>
</body>