I am having a major problem binding my data from TextBox to ViewModel To TextBlock. I have set up my following Xaml Code like so:

```
<Page
x:Class="digiBottle.MainPage"
DataContext="{Binding Source=UserProfile}"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:digiBottle"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" 
      DataContext="{Binding Source=UserProfile}">

    <TextBlock HorizontalAlignment="Left" Margin="219,72,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Height="32" Width="232" Text="{Binding userFirstName, Mode=OneWay}"/>
    <TextBox HorizontalAlignment="Left" Margin="39,72,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="111" Text="{Binding userFirstName, UpdateSourceTrigger=PropertyChanged}"/>

</Grid>

```

The .cs file I am trying to use as a source is defined as follows:

```
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace digiBottle.Model

```

{
 public class UserProfile : INotifyPropertyChanged
 {

```
    public int ID { get; set; }
    public string userFirstName;
    public string userLastName { get; set; }
    public int age { get; set; }
    public int weight { get; set; }
    public int height { get; set; }
    public DateTime signupTime { get; set; }

    public event PropertyChangedEventHandler PropertyChanged;

    public UserProfile()
    {
        userFirstName = "First Name";
    }

    private void RaisePropertyChanged(string propertyName)
    {
        if (this.PropertyChanged != null)
        {
            this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

    }

    public UserProfile getCopy()
    {
        UserProfile copy = (UserProfile)this.MemberwiseClone();
        return copy;
        }
    }
}

```

What am i doing wrong when trying to bind my TextBox and TextBlock to userFirstName in the UserProfile.cs Source. ANy help would be a major help!

Thank you