delete the last three lines

how can i delete the last three lines from a .txt file
if they was empty?

VB Code:

tmp = Mid(tmp, 1, Len(tmp) - 6)

Possibly another way

VB Code:

Dim Prts() As String
Dim txtFile As String
 
'Read the file
Open "D:\test.txt" For Input As #1
    txtFile = Input(FileLen("D:\test.txt"), 1)
Close #1
 
'Split the text
Prts() = Split(txtFile, vbCrLf)
 
'If the last three lines are empty then remove them
If Prts(UBound(Prts)) = "" And Prts(UBound(Prts) - 1) = "" And Prts(UBound(Prts) - 2) = "" Then
    ReDim Preserve Prts(UBound(Prts) - 3)
End If
 
'Re put the parts back together
txtFile = Join(Prts(), vbCrLf)
 
'Write it back
Open "D:\test.txt" For Output As #1
    Print #1, txtFile
Close #1