Serial VB 2005 pic 16f877a problems

[Snap]

I finaly did it (or should I say We....Mr e).The program works fine.
The key hang ups were add in a "z" in the VB write code and sending code all the time to the pic. Im sure there are way better ways of doing this but this works.
You need a pic and a 1620 temp ic and a serial converter and a pc.
here is the code and thank you everyone who helped especially the big E.
Snap
VB2005 code

 Public Class Form1
    Dim WithEvents serialport As New IO.Ports.SerialPort
    Dim temperature As Integer

    Dim setting As Decimal


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If serialport.IsOpen Then
            serialport.Close()

        End If
        With serialport
            .PortName = "com1"
            .BaudRate = 9600
            .Parity = IO.Ports.Parity.None
            .DataBits = 8
            .StopBits = IO.Ports.StopBits.One
            '.DtrEnable = True
            '.ReadBufferSize = 40
            .ReceivedBytesThreshold = 2
        End With
        TextBox4.Text = 23
        serialport.Open()
        serialport.Write(200 & "z")


    End Sub
    Private Sub Datarecieved(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles serialport.DataReceived
        TextBox1.Invoke(New mydelegate(AddressOf updatetextbox), New Object() {})

    End Sub
    Public Delegate Sub mydelegate()
    Public Sub updatetextbox()


        Dim mytemp As New temp
        mytemp.binary = serialport.ReadExisting
        Dim resultc As Decimal = celciusconversion(mytemp.binary)
        Dim resultf As Decimal = farconversion(resultc)
        TextBox1.Text = resultc
        TextBox2.Text = resultf
        If TextBox1.Text >= setting Then
            TextBox3.BackColor = Color.Green
            TextBox3.Text = "fan on"
            serialport.Write(100 & "z")

        ElseIf TextBox1.Text < setting Then
            TextBox3.BackColor = Color.Red
            TextBox3.Text = "fan off"
            serialport.Write(200 & "z")

        End If





    End Sub
    Public Function celciusconversion(ByVal datarecieved As String) As Decimal
        Return datarecieved * 0.5
    End Function

    Public Function farconversion(ByVal datarecieved As String) As Decimal
        Return (datarecieved * 1.8) + 32
    End Function
    
    Private Sub Label1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label1.Click

    End Sub

    Private Sub Label4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label4.Click

    End Sub

    Private Sub Label2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label2.Click

    End Sub

    Private Sub TextBox4_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox4.TextChanged
        setting = TextBox4.Text
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub
End Class

Temp Class

Public Class temp

    Private m_binary As String
    Private m_celsius As String
    Private m_farenheight As String

    Public Property binary()
        Get
            Return m_binary
        End Get
        Set(ByVal value)
            m_binary = value
        End Set
    End Property

    Public Property celsius()
        Get
            Return m_celsius
        End Get
        Set(ByVal value)
            m_celsius = value
        End Set


    End Property
    Public Property farenheight()
        Get
            Return m_farenheight
        End Get
        Set(ByVal value)
            m_farenheight = value

        End Set
    End Property

pic code

' Pic16f877a
' LCD should be connected as follows:
'       LCD     PIC
'       DB4     PortB.0
'       DB5     PortB.1
'       DB6     PortB.2
'       DB7     PortB.3
'       RS      PortB.5 (add 4.7K pullup resistor to 5 volts)
'       E       PortD.7
'       RW      Ground
'       Vdd     5 volts
'       Vss     Ground
'       Vo      20K potentiometer (or ground)
'       DB0-3   No connect
Include "MODEDEFS.BAS"
DEFINE LCD_DREG  PORTB
DEFINE LCD_DBIT   0
DEFINE LCD_RSREG  PORTB
DEFINE LCD_RSBIT 5
DEFINE LCD_EREG  PORTD
DEFINE LCD_EBIT 7
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATUS 50
ADCON1=%00000111

'
RST var portd.2
DQ var portd.0
CLK var portd.1
temp var word 'storage for temperature
pcsig var word
'portc=0
'trisc=0
HIGH PORTD.3    ' Serial OUT idle state
pause 500


'
low rst 'reset 1620
'
lcdout $fe,1,"Temp in Degrees C"

' Main loop
mainloop:
RST = 1'enable device might be high
Shiftout DQ,CLK,LSBFIRST,[$ee] 'send read command
RST = 0 ' reset device
Pause 1000 ' wait for conversion to compleate
'
RST = 1 ' SAA
Shiftout DQ,CLK,LSBFIRST, [$aa] ' send read command
Shiftin DQ,CLK,LSBPRE, [temp\9]'read 9 bits temp
RST = 0
lcdout $fe,1,dec(temp>>1), ".", dec(temp.0*5), " Degrees C"
serout portd.3,t9600,[#temp]

serin portc.4,t9600,#pcsig
if pcsig = 100 then high portc.5
if pcsig = 300 then goto mainloop

if pcsig = 200 then low portc.5

goto mainloop

END

[RudyPutra123]

Sorry Mr. Snap...

Can you tell me about meaning of code visual basic there line by line...
I wanna to learn visual basic, but I'm a Beginner !!

Please help me Mr.