<select size="5" id="users">
    <option value="Kelly">Kelly</option>
    <option value="Kylee">Kylee</option>
    <option value="Nathan">Nathan</option>
</select>

<input type="hidden" id="userList" runat="server" value="Kelly,Kylee,Nathan"/>

var $users = $('#users');
var $usersList = $('#usersList');

$users.append($('<option></option>').val('New Entry Value').html('New Entry Text'));

var newUserList = '';
var $options = $('#users').children('option');

$.each($options, function(index, value) {
	newUserList = newUserList + $options[index].value + ',';
}); 			

$usersList.val(newUserList.substr(0, newUserList.length-1));

<asp:UpdatePanel ID="UpdateRoles" runat="server">
    <ContentTemplate>
        <table>
            <tr>
                <td style="height: 180px; vertical-align: top;">
                    Active Roles<br />
                    <asp:ListBox ID="lstAdd" runat="server" Width="300px" OnSelectedIndexChanged="lstAdd_SelectedIndexChanged" Rows="10"></asp:ListBox>
                </td>
                <td style="height: 180px">
                    <asp:Button ID="AddRole" runat="server" Text="->" OnClick="AddRole_Click1" />
                    <br />
                    <asp:Button ID="RemoveRole" runat="server" Text="<-" OnClick="RemoveRole_Click" />
                </td>
                <td style="height: 180px; vertical-align: top;">
                    InActive Roles<br />
                    <asp:ListBox ID="lstRemove" runat="server" Width="300px" OnSelectedIndexChanged="lstRemove_SelectedIndexChanged" Rows="10"></asp:ListBox>
                </td>
            </tr>
        </table>
    </ContentTemplate>
</asp:UpdatePanel>

protected void AddRole_Click1(object sender, EventArgs e)
{
	if (lstAdd.SelectedIndex > -1)
	{
		lstRemove.Items.Add(lstAdd.SelectedItem);
		lstAdd.Items.RemoveAt(lstAdd.SelectedIndex);
	}
}

protected void RemoveRole_Click(object sender, EventArgs e)
{
	if (lstRemove.SelectedIndex > -1)
	{
		lstAdd.Items.Add(lstRemove.SelectedItem);
		lstRemove.Items.RemoveAt(lstRemove.SelectedIndex);
	}
}

[DataContract]
public class Member
{
	[DataMember]
	public int MemberId;

	[DataMember]
	public string CustomerCode;

	[DataMember]
	public string DelToCode;
}

[DataContract]
public class Rule
{
	[DataMember]
	public int RuleId;

	[DataMember]
	public string Name;

	[DataMember]
	public bool Enabled;

	[DataMember]
	public List<Member> Members;
}

[OperationContract]
[WebInvoke(
	RequestFormat = WebMessageFormat.Json,
	ResponseFormat = WebMessageFormat.Json,
	BodyStyle = WebMessageBodyStyle.WrappedRequest)
]
bool UpdateRule(Rule rule);

public bool UpdateRule(Rule rule)
{
	// Do Update Using Object
}

<fieldset class="withborder" id="manageRule">
<legend>Rule Update</legend>
<ol>
	<li>
		<label class="left">
			Rule ID<em>*</em></label>
		<input type="text" class="medium disabled" id="ruleId">
	</li>
	<li>
		<label class="left">
			Name<em>*</em></label>
		<input type="text" class="medium" maxlength="5" id="ruleName">
	</li>
	<li>
		<label class="left">
			Enabled<em>*</em></label>
		<input type="checkbox" class="checkBox" id="ruleEnabled" checked="checked">
	</li>
	<li>
		<label class="left">
			Assigned<em>*</em></label>
		<div>
			<div class="dropZone available">
				<ul class="connectedSortable ui-sortable" id="available" style="">
					<li id="MemberId_1" class="ui-state-highlight">Red</li>
					<li id="MemberId_2" class="ui-state-highlight">Green</li>
				</ul>
			</div>
			<div class="dropZone included">
				<ul class="connectedSortable ui-sortable" id="included" style="">
					<li id="MemberId_3" class="ui-state-highlight">Blue</li>
					<li id="MemberId_4" class="ui-state-highlight">Yellow</li>
					<li id="MemberId_5" class="ui-state-highlight">Orange</li>
				</ul>
			</div>
		</div>
	</li>
	<li style="text-align: right;">
		<input type="button" value="Update Rule" text="Add" id="updateRule">
	</li>
</ol>
</fieldset>

function UpdateRule() {
	var rule;

	rule.RuleId = parseInt($('#ruleId').val());
	rule.Name = $('#ruleName').val();
	rule.Enabled = $('#ruleEnabled').is(':checked');

	var $includedMembers = $('#included > li');

	rule.Members = [];

	// This is where you parse / add the values of your list (listbox, li, etc...)
	if ($includedMembers.length > 0) {
		$.each($includedMembers, function (index, value) {
			var id = $includedMembers[index].id.replace('MemberId_', '');
			var name = $includedMembers[index].firstChild.data.split(' - ');
			var member = { 'CustomerCode': name[0], 'DelToCode': name[1], 'MemberId': id };
			rule.Members.push(member);
		});
	}

	$.ajax({
		url: '/Service/ExampleWCFService.svc/UpdateRule',
		contentType: 'application/json; charset=utf-8',
		dataType: 'json',
		type: 'POST',
		data: JSON.stringify({ 'rule': rule }),
		success: function (rule) {
			// Do Something On Success
		}
	});
}

<html>
<head>
    <title>Demo - Covnert JSON to CSV</title>
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
    <script type="text/javascript" src="https://github.com/douglascrockford/JSON-js/raw/master/json2.js"></script>

    <script type="text/javascript">
		// JSON to CSV Converter
        function ConvertToCSV(objArray) {
            var array = typeof objArray != 'object' ? JSON.parse(objArray) : objArray;
            var str = '';

            for (var i = 0; i < array.length; i++) {
                var line = '';
                for (var index in array[i]) {
                    if (line != '') line += ','

                    line += array[i][index];
                }

                str += line + '\r\n';
            }

            return str;
        }

		// Example
        $(document).ready(function () {

			// Create Object
            var items = [
				  { name: "Item 1", color: "Green", size: "X-Large" },
				  { name: "Item 2", color: "Green", size: "X-Large" },
				  { name: "Item 3", color: "Green", size: "X-Large" }];

			// Convert Object to JSON
			var jsonObject = JSON.stringify(items);

			// Display JSON
            $('#json').text(jsonObject);

			// Convert JSON to CSV & Display CSV
            $('#csv').text(ConvertToCSV(jsonObject));
        });
    </script>
</head>
<body>
    <h1>
        JSON</h1>
    <pre id="json"></pre>
    <h1>
        CSV</h1>
    <pre id="csv"></pre>
</body>
</html>

[{"name":"Item 1","color":"Green","size":"X-Large"},{"name":"Item 2","color":"Green","size":"X-Large"},{"name":"Item 3","color":"Green","size":"X-Large"}]

Item 1,Green,X-Large
Item 2,Green,X-Large
Item 3,Green,X-Large