Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents GroupBox1 As System.Windows.Forms.GroupBox
    Friend WithEvents GroupBox2 As System.Windows.Forms.GroupBox
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents TxtStart As System.Windows.Forms.TextBox
    Friend WithEvents Label3 As System.Windows.Forms.Label
    Friend WithEvents TxtEnd As System.Windows.Forms.TextBox
    Friend WithEvents TxtPrice As System.Windows.Forms.TextBox
    Friend WithEvents Label4 As System.Windows.Forms.Label
    Friend WithEvents TxtGallons As System.Windows.Forms.TextBox
    Friend WithEvents Label5 As System.Windows.Forms.Label
    Friend WithEvents TxtMiles As System.Windows.Forms.TextBox
    Friend WithEvents Label6 As System.Windows.Forms.Label
    Friend WithEvents txtMPG As System.Windows.Forms.TextBox
    Friend WithEvents Label7 As System.Windows.Forms.Label
    Friend WithEvents TxtCost As System.Windows.Forms.TextBox
    Friend WithEvents Label8 As System.Windows.Forms.Label
    Friend WithEvents TxtMileCost As System.Windows.Forms.TextBox
    Friend WithEvents Label9 As System.Windows.Forms.Label
    Friend WithEvents BtnCalc As System.Windows.Forms.Button
    Friend WithEvents BtnReset As System.Windows.Forms.Button
    Friend WithEvents BtnQuit As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label
        Me.GroupBox1 = New System.Windows.Forms.GroupBox
        Me.TxtEnd = New System.Windows.Forms.TextBox
        Me.Label3 = New System.Windows.Forms.Label
        Me.TxtStart = New System.Windows.Forms.TextBox
        Me.Label2 = New System.Windows.Forms.Label
        Me.GroupBox2 = New System.Windows.Forms.GroupBox
        Me.TxtPrice = New System.Windows.Forms.TextBox
        Me.Label4 = New System.Windows.Forms.Label
        Me.TxtGallons = New System.Windows.Forms.TextBox
        Me.Label5 = New System.Windows.Forms.Label
        Me.TxtMiles = New System.Windows.Forms.TextBox
        Me.Label6 = New System.Windows.Forms.Label
        Me.txtMPG = New System.Windows.Forms.TextBox
        Me.Label7 = New System.Windows.Forms.Label
        Me.TxtCost = New System.Windows.Forms.TextBox
        Me.Label8 = New System.Windows.Forms.Label
        Me.TxtMileCost = New System.Windows.Forms.TextBox
        Me.Label9 = New System.Windows.Forms.Label
        Me.BtnCalc = New System.Windows.Forms.Button
        Me.BtnReset = New System.Windows.Forms.Button
        Me.BtnQuit = New System.Windows.Forms.Button
        Me.GroupBox1.SuspendLayout()
        Me.GroupBox2.SuspendLayout()
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.AutoSize = True
        Me.Label1.Font = New System.Drawing.Font("Microsoft Sans Serif", 24.0!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label1.Location = New System.Drawing.Point(232, 32)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(209, 49)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "Trip Costs"
        '
        'GroupBox1
        '
        Me.GroupBox1.Controls.Add(Me.TxtGallons)
        Me.GroupBox1.Controls.Add(Me.Label5)
        Me.GroupBox1.Controls.Add(Me.TxtPrice)
        Me.GroupBox1.Controls.Add(Me.Label4)
        Me.GroupBox1.Controls.Add(Me.TxtEnd)
        Me.GroupBox1.Controls.Add(Me.Label3)
        Me.GroupBox1.Controls.Add(Me.TxtStart)
        Me.GroupBox1.Controls.Add(Me.Label2)
        Me.GroupBox1.Location = New System.Drawing.Point(24, 104)
        Me.GroupBox1.Name = "GroupBox1"
        Me.GroupBox1.Size = New System.Drawing.Size(312, 240)
        Me.GroupBox1.TabIndex = 1
        Me.GroupBox1.TabStop = False
        Me.GroupBox1.Text = "Trip Info"
        '
        'TxtEnd
        '
        Me.TxtEnd.Location = New System.Drawing.Point(184, 80)
        Me.TxtEnd.Name = "TxtEnd"
        Me.TxtEnd.Size = New System.Drawing.Size(112, 22)
        Me.TxtEnd.TabIndex = 3
        Me.TxtEnd.Text = ""
        '
        'Label3
        '
        Me.Label3.Font = New System.Drawing.Font("Microsoft Sans Serif", 10.2!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label3.Location = New System.Drawing.Point(16, 80)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(152, 32)
        Me.Label3.TabIndex = 2
        Me.Label3.Text = "End Odometer:"
        '
        'TxtStart
        '
        Me.TxtStart.Location = New System.Drawing.Point(184, 40)
        Me.TxtStart.Name = "TxtStart"
        Me.TxtStart.Size = New System.Drawing.Size(112, 22)
        Me.TxtStart.TabIndex = 1
        Me.TxtStart.Text = ""
        '
        'Label2
        '
        Me.Label2.Font = New System.Drawing.Font("Microsoft Sans Serif", 10.2!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label2.Location = New System.Drawing.Point(16, 40)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(152, 32)
        Me.Label2.TabIndex = 0
        Me.Label2.Text = "Start Odometer:"
        '
        'GroupBox2
        '
        Me.GroupBox2.Controls.Add(Me.TxtMileCost)
        Me.GroupBox2.Controls.Add(Me.Label9)
        Me.GroupBox2.Controls.Add(Me.TxtCost)
        Me.GroupBox2.Controls.Add(Me.Label8)
        Me.GroupBox2.Controls.Add(Me.txtMPG)
        Me.GroupBox2.Controls.Add(Me.Label7)
        Me.GroupBox2.Controls.Add(Me.TxtMiles)
        Me.GroupBox2.Controls.Add(Me.Label6)
        Me.GroupBox2.Location = New System.Drawing.Point(360, 104)
        Me.GroupBox2.Name = "GroupBox2"
        Me.GroupBox2.Size = New System.Drawing.Size(336, 240)
        Me.GroupBox2.TabIndex = 2
        Me.GroupBox2.TabStop = False
        Me.GroupBox2.Text = "Results"
        '
        'TxtPrice
        '
        Me.TxtPrice.Location = New System.Drawing.Point(184, 120)
        Me.TxtPrice.Name = "TxtPrice"
        Me.TxtPrice.Size = New System.Drawing.Size(112, 22)
        Me.TxtPrice.TabIndex = 5
        Me.TxtPrice.Text = ""
        '
        'Label4
        '
        Me.Label4.Font = New System.Drawing.Font("Microsoft Sans Serif", 10.2!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label4.Location = New System.Drawing.Point(16, 120)
        Me.Label4.Name = "Label4"
        Me.Label4.Size = New System.Drawing.Size(176, 32)
        Me.Label4.TabIndex = 4
        Me.Label4.Text = "Gas Price Per Gallon:"
        '
        'TxtGallons
        '
        Me.TxtGallons.Location = New System.Drawing.Point(184, 176)
        Me.TxtGallons.Name = "TxtGallons"
        Me.TxtGallons.Size = New System.Drawing.Size(112, 22)
        Me.TxtGallons.TabIndex = 7
        Me.TxtGallons.Text = ""
        '
        'Label5
        '
        Me.Label5.Font = New System.Drawing.Font("Microsoft Sans Serif", 10.2!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label5.Location = New System.Drawing.Point(16, 176)
        Me.Label5.Name = "Label5"
        Me.Label5.Size = New System.Drawing.Size(168, 32)
        Me.Label5.TabIndex = 6
        Me.Label5.Text = "Gallons Purchased:"
        '
        'TxtMiles
        '
        Me.TxtMiles.Location = New System.Drawing.Point(192, 40)
        Me.TxtMiles.Name = "TxtMiles"
        Me.TxtMiles.ReadOnly = True
        Me.TxtMiles.Size = New System.Drawing.Size(112, 22)
        Me.TxtMiles.TabIndex = 3
        Me.TxtMiles.Text = ""
        '
        'Label6
        '
        Me.Label6.Font = New System.Drawing.Font("Microsoft Sans Serif", 10.2!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label6.Location = New System.Drawing.Point(24, 40)
        Me.Label6.Name = "Label6"
        Me.Label6.Size = New System.Drawing.Size(152, 32)
        Me.Label6.TabIndex = 2
        Me.Label6.Text = "Miles Traveled"
        '
        'txtMPG
        '
        Me.txtMPG.Location = New System.Drawing.Point(192, 80)
        Me.txtMPG.Name = "txtMPG"
        Me.txtMPG.ReadOnly = True
        Me.txtMPG.Size = New System.Drawing.Size(112, 22)
        Me.txtMPG.TabIndex = 5
        Me.txtMPG.Text = ""
        '
        'Label7
        '
        Me.Label7.Font = New System.Drawing.Font("Microsoft Sans Serif", 10.2!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label7.Location = New System.Drawing.Point(24, 80)
        Me.Label7.Name = "Label7"
        Me.Label7.Size = New System.Drawing.Size(152, 32)
        Me.Label7.TabIndex = 4
        Me.Label7.Text = "Miles Per Gallon"
        '
        'TxtCost
        '
        Me.TxtCost.Location = New System.Drawing.Point(192, 120)
        Me.TxtCost.Name = "TxtCost"
        Me.TxtCost.ReadOnly = True
        Me.TxtCost.Size = New System.Drawing.Size(112, 22)
        Me.TxtCost.TabIndex = 7
        Me.TxtCost.Text = ""
        '
        'Label8
        '
        Me.Label8.Font = New System.Drawing.Font("Microsoft Sans Serif", 10.2!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label8.Location = New System.Drawing.Point(24, 120)
        Me.Label8.Name = "Label8"
        Me.Label8.Size = New System.Drawing.Size(152, 32)
        Me.Label8.TabIndex = 6
        Me.Label8.Text = "Total Gas Cost"
        '
        'TxtMileCost
        '
        Me.TxtMileCost.Location = New System.Drawing.Point(192, 168)
        Me.TxtMileCost.Name = "TxtMileCost"
        Me.TxtMileCost.ReadOnly = True
        Me.TxtMileCost.Size = New System.Drawing.Size(112, 22)
        Me.TxtMileCost.TabIndex = 9
        Me.TxtMileCost.Text = ""
        '
        'Label9
        '
        Me.Label9.Font = New System.Drawing.Font("Microsoft Sans Serif", 10.2!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label9.Location = New System.Drawing.Point(24, 168)
        Me.Label9.Name = "Label9"
        Me.Label9.Size = New System.Drawing.Size(152, 32)
        Me.Label9.TabIndex = 8
        Me.Label9.Text = "Cost Per Mile"
        '
        'BtnCalc
        '
        Me.BtnCalc.Location = New System.Drawing.Point(112, 400)
        Me.BtnCalc.Name = "BtnCalc"
        Me.BtnCalc.Size = New System.Drawing.Size(112, 48)
        Me.BtnCalc.TabIndex = 3
        Me.BtnCalc.Text = "Calculate"
        '
        'BtnReset
        '
        Me.BtnReset.Location = New System.Drawing.Point(256, 400)
        Me.BtnReset.Name = "BtnReset"
        Me.BtnReset.Size = New System.Drawing.Size(112, 48)
        Me.BtnReset.TabIndex = 4
        Me.BtnReset.Text = "Reset"
        '
        'BtnQuit
        '
        Me.BtnQuit.Location = New System.Drawing.Point(400, 400)
        Me.BtnQuit.Name = "BtnQuit"
        Me.BtnQuit.Size = New System.Drawing.Size(112, 48)
        Me.BtnQuit.TabIndex = 5
        Me.BtnQuit.Text = "Quit"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 15)
        Me.ClientSize = New System.Drawing.Size(712, 512)
        Me.Controls.Add(Me.BtnQuit)
        Me.Controls.Add(Me.BtnReset)
        Me.Controls.Add(Me.BtnCalc)
        Me.Controls.Add(Me.GroupBox2)
        Me.Controls.Add(Me.GroupBox1)
        Me.Controls.Add(Me.Label1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.GroupBox1.ResumeLayout(False)
        Me.GroupBox2.ResumeLayout(False)
        Me.ResumeLayout(False)

    End Sub

#End Region

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

    End Sub

    Private Sub BtnReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnReset.Click
        TxtStart.Text = ""
        TxtEnd.Text = ""
        TxtPrice.Text = ""
        TxtGallons.Text = ""
        TxtMiles.Text = ""
        txtMPG.Text = ""
        TxtCost.Text = ""
        TxtMileCost.Text = ""
    End Sub

    Private Sub BtnCalc_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnCalc.Click
        Dim start As Double
        Dim endOdom As Double
        Dim price As Double
        Dim gallons As Double
        Dim miles As Double
        Dim mpg As Double
        Dim cost As Double
        Dim mileCost As Double
        ' first validate all inputs

        ' use boolean to avoid deep nesting
        Dim dataOk As Boolean = True

        ' check starting odometer
        If IsNumeric(TxtStart.Text) Then
            start = Convert.ToDouble(TxtStart.Text)
            If start < 0 Or start > 999999.9 Then
                MsgBox("Odometer start is outside odometer range")
                dataOk = False
            End If
        Else
            MsgBox("Odometer start must be number")
            dataOk = False
        End If

        ' check ending odometer
        If IsNumeric(TxtEnd.Text) Then
            endOdom = Convert.ToDouble(TxtEnd.Text)
            If endOdom < 0 Or endOdom > 999999.9 Then
                MsgBox("Odometer end is outside odometer range")
                dataOk = False
            End If
        Else
            MsgBox("Odometer end must be number")
            dataOk = False
        End If

        ' make sure end is after start
        If start > endOdom Then
            MsgBox("Did you drive in reverse the whole way?")
            dataOk = False
        End If

        ' check price of gas
        If IsNumeric(TxtPrice.Text) Then
            price = Convert.ToDouble(TxtPrice.Text)
            ' assume price has to be between 50 cents and $10
            If price < 0.5 Or price > 10 Then
                MsgBox("price is outside normal range (.5 to 10)")
                dataOk = False
            End If
        Else
            MsgBox("Price must be number")
            dataOk = False
        End If

        ' check number of gallons
        If IsNumeric(TxtGallons.Text) Then
            gallons = Convert.ToDouble(TxtGallons.Text)
            ' assume gallons has to be between .1  and 30
            If gallons < 0.1 Or gallons > 30 Then
                MsgBox("Gallons is outside normal range (.1 to 30)")
                dataOk = False
            End If
        Else
            MsgBox("Gallons must be number")
            dataOk = False
        End If

        '==============================================
        ' now before going on, make sure all data is ok
        '==============================================
        If dataOk Then
            ' calculate miles traveled, miles per gallon, total cost, and cost per mile
            miles = endOdom - start
            mpg = miles / gallons
            cost = price * gallons
            mileCost = cost / miles

            ' put results out to form
            TxtMiles.Text = miles.ToString("n1")
            txtMPG.Text = mpg.ToString("n1")
            TxtCost.Text = cost.ToString("c")
            TxtMileCost.Text = mileCost.ToString("c3")
        End If

    End Sub
End Class