vb串口 出错

1楼指明的正确,LZ的代码存在明显错误,现修改LZ的代码:
Option Explicit
Dim sj(2) As String
Dim sum As Integer

Private Sub Command1_Click()
If MSComm1.PortOpen = True Then
MSComm1.Output = "key;utility"
MSComm1.Output = "key：ref"
MSComm1.Output = "KEY；display"
Print MSComm1.OutBufferCount
End If
End Sub

Private Sub Command2_Click()
If MSComm1.PortOpen = True Then
Text2.Text = MSComm1.Input
End If
End Sub

Private Sub Command3_Click()
If Combo_RS232.Text = "COM1" Then
MSComm1.CommPort = 1
ElseIf Combo_RS232.Text = "COM2" Then
MSComm1.CommPort = 2
ElseIf Combo_RS232.Text = "COM3" Then
MSComm1.CommPort = 3
End If
If Combo_Baudrate.Text = "9600" Then
MSComm1.Settings = "9600,n,8,1