Always getting DependencyProperty.unsetvalue - wpf

Question

So am testing multibinding in wpf and i have three text boxes which should get the year,month,day and my converter class should return a date with those inputs..pretty simple.
But in my convert method the values[0] is always unset that is i am always getting Dependencyproperty.UnsetValue even if get give it an initial value.
XAML
<Window x:Class="WpfApplication2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:s="clr-namespace:System;assembly=mscorlib"
xmlns:src="clr-namespace:WpfApplication2"
Title="MultiBinding Demo" Width="200" Height="200">
<Window.Resources>
<src:DateConverter x:Key="myConverter" />
</Window.Resources>
<StackPanel Orientation="Horizontal">
<StackPanel.Resources>
</StackPanel.Resources>
<TextBox Name="tb1" Margin="10" Width="Auto" Height="20"></TextBox>
<TextBox Name="tb2" Margin="10" Width="20" Height="20" ></TextBox>
<TextBox Name="tb3" Width="20" Height="20" ></TextBox>
<Label Name="Date" Width="50" Height="25" Margin="5" >
<Label.Content>
<MultiBinding Converter="{StaticResource myConverter}" Mode="OneWay">
<Binding ElementName="tbl" Path="Text" />
<Binding ElementName="tb2" Path="Text" />
<Binding ElementName="tb3" Path="Text" />
</MultiBinding>
</Label.Content>
</Label>
</StackPanel>
DATECONVERTER CLASS
class DateConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (values[0] == DependencyProperty.UnsetValue || values[1] == DependencyProperty.UnsetValue || values[2] == DependencyProperty.UnsetValue)
{
return "";
}
else
{
int year = (int)values[0];
int month = (int)values[1];
int day = (int)values[2];
DateTime date = new DateTime(year, month, day);
return date.ToShortDateString();
}
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}

Answer 1

I'm looking at your XAML, and it looks like your first TextBox is named tb1 (number 1) but in the binding you're referencing element name tbl (letter L).