Why is my XAML failing to parse (start tag does not match end tag)?

Why is my XAML failing to parse (start tag does not match end tag)?

I'm getting this error:
Error:The 'Grid' start tag on line 17 position 6 does not match the end
tag of 'phone:PhoneApplicationPage'.
I have tried many things to solve this error, but have failed. Please tell
me how to solve this.
My code is:
<phone:PhoneApplicationPage
x:Class="wmvplayer.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"
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="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<!--TitlePanel contains the name of the application and page title-->
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
<TextBlock Text="WMV Player" Margin="9,-7,0,0"
Style="{StaticResource PhoneTextTitle1Style}"/>
</StackPanel>
<StackPanel Background="Black">
<!-- To interactively stop, pause, and play the media, the
LoadedBehavior
property of the MediaElement must be set to "Manual". -->
<MediaElement Source="media\numbers.wmv" Name="myMediaElement"
Width="450" Height="250" Stretch="Fill"
MediaOpened="Element_MediaOpened" MediaEnded="Element_MediaEnded"/>
<StackPanel HorizontalAlignment="Center" Width="450"
Orientation="Horizontal">
<Image Source="play.png" MouseEnter="OnMouseDownPlayMedia"
Margin="5" />
<!-- Pause button. -->
<Image Source="pause.png" MouseEnter="OnMouseDownPauseMedia"
Margin="5" />
<!-- Stop button. -->
<Image Source="stop.png" MouseLeave="OnMouseDownStopMedia"
Margin="5" />
<!-- Volume slider. This slider allows a Volume range between
0 and 1. -->
<TextBlock Foreground="White" VerticalAlignment="Center"
Margin="5" >Volume</TextBlock>
<Slider Name="volumeSlider" VerticalAlignment="Center"
ValueChanged="ChangeMediaVolume"
Minimum="0" Maximum="1" Value="0.5" Width="70"/>
<!-- Volume slider. This slider allows you to change the speed
of the media playback. -->
<TextBlock Foreground="White" Margin="5"
VerticalAlignment="Center">Speed</TextBlock>
<Slider Name="speedRatioSlider" VerticalAlignment="Center"
ValueChanged="ChangeMediaSpeedRatio"
Value="1" Width="70" />
<!-- Seek to slider. Ths slider allows you to jump to
different parts of the media playback. -->
<TextBlock Foreground="White" Margin="5"
VerticalAlignment="Center">Seek To</TextBlock>
<Slider Name="timelineSlider" Margin="5"
ValueChanged="SeekToMediaPosition" Width="70"/>
</StackPanel>
</StackPanel>
</Grid> </phone:PhoneApplicationPage>