Option Explicit On 
Option Strict On

Public Class Form1
    Inherits System.Windows.Forms.Form

    Const min As Integer = 1
    Const max As Integer = 100
    Dim actual As Integer
    Friend WithEvents rtbGuesses As System.Windows.Forms.RichTextBox
    Friend WithEvents Label4 As System.Windows.Forms.Label
    Dim randGen As New Random


#Region " Windows Form Designer generated code "

 ... deleted - code generated by IDE ...

#End Region

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        LblQuery.Text = "I'm Thinking of a Number Between " & min & " and " & max
        actual = randGen.Next(1, max + 1)

        MsgBox("the actual is: " & actual)
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Me.Close()

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim guess As Integer
        Dim guesses As Integer
        Dim isConverted As Boolean
        isConverted = Integer.TryParse(TxtNumber.Text, guesses)
        ' don't need to check # guesses because it is read only
        guesses = guesses + 1
        ' ensure valid input
        isConverted = Integer.TryParse(TxtGuess.Text, guess)
        If isConverted Then
            TxtNumber.Text = guesses.ToString("n0")
            If guess = actual Then
                'got it right
                rtbGuesses.AppendText(guess.ToString() & "  Correct" & ControlChars.NewLine)
                LblFeedback.Text = "You're right!!!!"
                LblFeedback.ForeColor = Color.Red
            ElseIf guess > actual Then
                rtbGuesses.AppendText(guess.ToString() & "  High" & ControlChars.NewLine)
                LblFeedback.Text = "Your guess is too high"
            Else
                rtbGuesses.AppendText(guess.ToString() & "  Low" & ControlChars.NewLine)
                LblFeedback.Text = "Your guess is too low"
            End If
            TxtGuess.Clear()
            TxtGuess.Focus()

        Else
            MsgBox("Please enter a whole number")
        End If
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        actual = randGen.Next(1, max + 1)
        ' old way of random number generation!!
        ' actual = Convert.ToInt32((max - min + 1) * Rnd() + min)
        TxtNumber.Text = "0"
        TxtGuess.Text = ""
        LblFeedback.Text = ""
        LblFeedback.ForeColor = Color.Black
        rtbGuesses.Clear()
    End Sub
End Class