Windows phone 7 scrollviewer problem

I am not able to scroll through the page in wp7 . eventhough i have added scrollview it still doesnt work.

<phone:PhoneApplicationPage 
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="860"
x:Class="sastadeal.PhonePage1"
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}"
Foreground="{StaticResource PhoneForegroundBrush}"
Orientation="Portrait"
shell:SystemTray.IsVisible="True" Height="1768">

<!--LayoutRoot is the root grid where all page content is placed-->
<Grid x:Name="LayoutRoot" Background="Transparent" Height="1768">
    <ScrollViewer>

        <!--TitlePanel contains the name of the application and page title-->
<!--TitlePanel contains the name of the application and page title-->

    <Grid x:Name="ContentPanel" Margin="24,8,0,-8" Background="#FF61B1DE" Height="1768" >

        <Image Height="76" Margin="8,8,0,0" Source="logo.png" Stretch="Fill" VerticalAlignment="Top"/>

        <TextBlock HorizontalAlignment="Left" Margin="35,124,0,0" TextWrapping="Wrap" Text="Account Purpose" VerticalAlignment="Top" Foreground="Black"/>
        <ListBox x:Name="lb" Height="70" Margin="36,161,185,0" VerticalAlignment="Top" FontSize="24" Background="#FF00BEEF">
            <ListBoxItem x:Name="lb_vendor" Content="Launch &amp; Grab Deals"/>
            <ListBoxItem x:Name="lb_customer" Content="Grab Deals"/>
        </ListBox>
        <TextBlock HorizontalAlignment="Left" Margin="32,252,0,0" TextWrapping="Wrap" Text="Ente