跪求大神看一下这段代码 找不到子程序 错在哪里

同学给我发的程序让我看一下 不过我学的是C 根本不知道这是干嘛的
急求VB吧大神给看一下 他说错误是“找不到子程序”
Private Sub Command1_Click()
CommonDialog1.FileName = " "
CommonDialog1.Filter = "txt文件|*.txt"
CommonDialog1.InitDir = "D:\zhoujp\"
CommonDialog1.ShowSave
End Sub Private Sub Command2_Click()
Dim status As Long
Dim defrm As Long
Dim vi As Long
Dim strRes As String * 200
Dim strRes1 As String * 20
Dim strRes2 As String * 20
Dim actual As Long
status = viOpenDefaultRM(defrm)
status = viOpen(defrm, "TCPIP0::192.168.1.101::inst0::INSTR", 0, 0, vi)
status = viWrite(vi, ":func:imp ZtD" + Chr$(10), 16, actual) For j = 1.5 To 6 Step 0.01
sd$ = Str(10 ^ j)
sdf$ = ":freq" & sd$ & "hz" status = viWrite(vi, sdf$ + Chr$(10), 20, actual)
status = viWrite(vi, "*trg" + Chr$(10), 5, actual)
status = viWrite(vi, "fetch?" + Chr$(10), 7, actual)
Call viRead(vi, strRes, 200, actual)
strRes1 = Mid(strRes, 1, 12)
strRes2 = Mid(strRes, 14, 12)
Open CommonDialog1.FileName For Append As #1
Print #1, 10 ^ j, strRes1, strRes2
Close #1
Next j
status = viClose(defrm)
MsgBox "测试结束", vbOKOnly, "提示信息" End Sub Private Sub Command3_Click()
Unload Me
End Sub