how to trigger vb by arduino

See more:

VB

VB10

Arduino

hello guys.. i wondering is there any wrong with my code since i try to run it just now and noting happen

code of arduino

const int threhold = 100;
int sensorReading;
int irs=0;
void setup()
{
 pinMode(irs, INPUT);
Serial.begin(9600);
}
void loop()
{
  sensorReading = analogRead(irs);
  if(sensorReading > threhold)
  {
   Serial.write("1");
  }
  else
  {
   Serial.write("0");
  }
  delay(100);
}

code of vb

Imports System.IO
Imports System.IO.Ports

Dim val As Integer

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        SerialPort1.Encoding = System.Text.Encoding.Default
        SerialPort1.Open()
        val = SerialPort1.ReadLine
        If val = 0 Then
            PictureBox1.Image = My.Resources.Button_Blank_Red_icon__1_
        ElseIf val = 1 Then
            PictureBox1.Image = My.Resources.Button_Blank_Green_icon_2
        End If
    End Sub