BindingExpression path error: 'username' property not found on 'lim'(pls help)

<Grid x:Name="ContentGrid" Margin="0,22,0,-22" Grid.Row="1">
           <ListBox Height="444" HorizontalAlignment="Left" Margin="20,81,0,0" Name="listBox1" VerticalAlignment="Top" Width="434" >
               <ListBox.ItemTemplate>
                   <DataTemplate>
                       <StackPanel Orientation="Horizontal">
                           <TextBlock Text="{Binding username}" />
                           <TextBlock Text="{Binding password}" />
                           <TextBlock Text="{Binding gender}" />
                       </StackPanel>
                   </DataTemplate>
               </ListBox.ItemTemplate>
           </ListBox>
       </Grid>

<phone:PhoneApplicationPage
    x:Class="Epromo.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True" >

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="83"/>
            <RowDefinition Height="685*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Margin="9,17,3,0"></StackPanel>
        <Button Content="On going"  HorizontalAlignment="Left" Margin="-5,85,0,0" VerticalAlignment="Top" Grid.RowSpan="2" Width="195"/>
        <Button Content="most view" HorizontalAlignment="Left" Margin="161,85,0,0" VerticalAlignment="Top" Grid.RowSpan="2" Width="186" RenderTransformOrigin="0.5,0.5"/>
        <Button Content="Coming soon" HorizontalAlignment="Left" Margin="321,85,-13,0" VerticalAlignment="Top" Grid.RowSpan="2" Width="170" FontSize="20" Height="72"/>
        <Grid x:Name="ContentGrid" Margin="0,22,0,-22" Grid.Row="1">
            <ListBox Height="444" HorizontalAlignment="Left" Margin="20,81,0,0" Name="listBox1" VerticalAlignment="Top" Width="434" >
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <TextBlock Text="{Binding username}" />
                            <TextBlock Text="{Binding password}" />
                            <TextBlock Text="{Binding gender}" />
                        </StackPanel>
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>
        </Grid>
        <Button Content="sign up" FontSize="17" Height="60" Name="signup" Width="120" Click="signup_Click" Margin="371,43,-11,647" Grid.RowSpan="2" />
        <TextBlock x:Name="ApplicationTitle" Style="{StaticResource PhoneTextNormalStyle}" FontSize="24" FontFamily="Times New Roman" Height="34" Margin="4,0,32,49">

                <Run Text="Epromo" /></TextBlock>
        <!--ContentPanel - place additional content here-->
    </Grid>

</phone:PhoneApplicationPage>

using Epromo.ServiceReference1;

namespace Epromo
{
    public partial class MainPage : PhoneApplicationPage
    {
        private Service1Client _serviceClient;
        // Constructor
        public MainPage()
        {
            InitializeComponent();
            Loaded += new RoutedEventHandler(Post_Loaded);
        }
        void Post_Loaded(object sender, EventArgs e)
        {
            _serviceClient = new Service1Client();
            _serviceClient.ListPostCompleted += new EventHandler<ListPostCompletedEventArgs>(getList_Completed);
            _serviceClient.ListPostAsync();

        }
        void getList_Completed(object sender, ListPostCompletedEventArgs e)
        {
            listBox1.ItemsSource = e.Result;
        }

        private void signup_Click(object sender, RoutedEventArgs e)
        {
            NavigationService.Navigate(new Uri("/signupPage.xaml", UriKind.Relative));
        }





    }
}