This must be simple, but I have trouble to get this solved ...

I have a mouse click event proc of which the sender type is a RadTextBoxItem. I need to know the textbox, so type TextBox or RadTextBox. How can this be done?

    public class MyCustomVisualItem : SimpleListViewVisualItem
    {
        private LightVisualElement _contentElementName;
        private LightVisualElement _contentElementState;
 
        private StackLayoutPanel _stackLayoutH;
        private StackLayoutPanel _stackLayoutV;
 
        private ImagePrimitive _image1;
        
        protected override void CreateChildElements()
        {
            base.CreateChildElements();
 
            _stackLayoutH = new StackLayoutPanel
            {
                Orientation = Orientation.Horizontal,
                EqualChildrenWidth = false
            };
 
            _stackLayoutV = new StackLayoutPanel
            {
                Orientation = Orientation.Vertical,
                EqualChildrenWidth = true,
                Margin = new Padding(10,0,0,0)
            };
 
            _image1 = new ImagePrimitive
            {
                Image = (Image)Resource1.ResourceManager.GetObject("Anonymous"),
                Alignment = ContentAlignment.MiddleLeft
            };
            _stackLayoutH.Children.Add(_image1);
 
 
            _contentElementName = new LightVisualElement
            {
                StretchHorizontally = true,
                Alignment = ContentAlignment.MiddleLeft,
                ImageAlignment = ContentAlignment.MiddleLeft,
                TextAlignment = ContentAlignment.MiddleLeft,
                Image = (Image)Resource1.ResourceManager.GetObject("Untitled_1s"),
                TextImageRelation = TextImageRelation.ImageBeforeText
            };
            _stackLayoutV.Children.Add(_contentElementName);
 
            _contentElementState = new LightVisualElement
            {
                StretchHorizontally = true,
                Alignment = ContentAlignment.MiddleLeft,
                TextAlignment = ContentAlignment.MiddleLeft,
                ForeColor = Color.Gray,
            };
            _stackLayoutV.Children.Add(_contentElementState);
 
            _stackLayoutH.Children.Add(_stackLayoutV);
 
            Children.Add(_stackLayoutH);
        }
 
        protected override void SynchronizeProperties()
        {
            base.SynchronizeProperties();
 
            Text = "";
            _contentElementName.Text = Convert.ToString(Data["Name"]);
            _contentElementState.Text = "Life is Good";
 
        }
 
        protected override Type ThemeEffectiveType
        {
            get
            {
                return typeof(SimpleListViewVisualItem);
            }
        }
    }

 	
	public RadForm1()
        {
            InitializeComponent();
            this.radListView1.Columns.Add("Name");
            this.radListView1.Items.Add(new ListViewDataItem("text"));
            this.radListView1.Items[0]["Name"] = "User";
        }
 
        private void radListView1_VisualItemCreating(object sender, Telerik.WinControls.UI.ListViewVisualItemCreatingEventArgs e)
        {
            e.VisualItem = new MyCustomVisualItem();
        }
 
        private void radListView1_SelectedItemChanged(object sender, EventArgs e)
        {
            int s = 2;
        }