Code:
Private Sub CheckStartList()
Dim a As Integer

If Option1(2).Value Then
    start_tag = Val(Text1(8))
    For a = 0 To List1(aa).ListCount - 1
        If List1(aa).List(a) > Val(start_tag) Then
            getStart = a
            Exit Sub
        Else
            getStart = -1
        End If
    Next
End If

If Option2(0).Value Then
    start_tag = Val(Text1(8))
    For a = 0 To List1(aa).ListCount - 1
        If List1(aa).List(a) < Val(start_tag) Then
            getStart = a
            Exit Sub
        Else
            getStart = -1
        End If
    Next
End If
End Sub


Private Sub CheckStopList()
Dim a, b As Integer

    If Option1(3).Value Then
        stop_tag = Val(Text1(9))
        For a = 0 To List1(aa).ListCount - 1
            If List1(aa).List(a) > Val(stop_tag) Then
                If a > 0 Then getStop = a - 1
                If a = 0 Then getStop = 0
                If getStop >= getStart Then Exit Sub
            Else
            getStop = List1(aa).ListCount - 1
            End If
        Next
    End If
    
    If Option2(1).Value Then
        stop_tag = Val(Text1(9))
        For a = 0 To List1(aa).ListCount - 1
            If List1(aa).List(a) < Val(stop_tag) Then
                If a > 0 Then getStop = a - 1
                If a = 0 Then getStop = 0
                If getStop >= getStart Then Exit Sub
            Else
            getStop = List1(aa).ListCount - 1
            End If
        Next
    End If    
End Sub 

Private Sub SaveLogFile_TXT()
        If chk_startLogging.Value = 1 Then
            If Option4(1).Value Then
                num = 1
                If cmb_channel.Text = "Channel 1" Then aa = 0
                If cmb_channel.Text = "Channel 2" Then aa = 1
                If cmb_channel.Text = "Channel 3" Then aa = 2
                If cmb_channel.Text = "Channel 4" Then aa = 3
                If cmb_channel.Text = "Channel 5" Then aa = 4
                If cmb_channel.Text = "Channel 6" Then aa = 5
                If cmb_channel.Text = "Channel 7" Then aa = 6
                If cmb_channel.Text = "Channel 8" Then aa = 7
    
                CheckStartList                
                CheckStopList
                    
                If List1(aa).List(0) <> "" Then
                    If getStart = -1 Then
                        Close #3
                        Exit Sub
                    End If
                    For c = getStart To getStop
                        Print #3, Format(num, "00000");
                        For b = 0 To 7
                            Print #3, Right$(Space(8) & List1(b).List©, 8);
                        Next b
                        Print #3,
                        num = num + 1
                    Next
                End If
                Close #3
            Exit Sub
            End If
        End If
End Sub


when running the code,there is no error...but sometimes the result is not correctly.....
i think the problem is inside the "CheckStartList" or "CheckStopList".....