BasicIO.vb

Public Class Form1
    ' Form Controls: Label LblContext, TextBox TbxInput, Button BtnSubmit
 
    Dim _name As String = vbNull
 
    Private Sub BtnSubmit_Click(sender As System.Object, e As System.EventArgs) Handles BtnSubmit.Click
        If TbxInput.Text <> _name Then
            If TbxInput.Text = "" Then
                TbxInput.BackColor = Color.Yellow
                MessageBox.Show("Please enter your name in the provided box", Application.ProductName)
                Exit Sub
            End If
            LblOutput.Text = "Hello " + TbxInput.Text
            _name = TbxInput.Text
        End If
    End Sub
End Class