Нужно пояснение одной строки - VB

Option Explicit
 
Private Type MARSH
nomer As String
na4alo As String
konec As String
End Type
 
Dim wer As String
Dim i As Integer
Dim Г± As Integer
Dim d As Integer
Dim marshrut(0 To 3) As MARSH
 
Private Sub Command1_Click()
i = i + 1
Label2.Caption = i + 1
marshrut(i).nomer = Text1.Text
marshrut(i).na4alo = Text2.Text
marshrut(i).konec = Text3.Text
If i = 3 Then Command1.Enabled = False
If i = 3 Then Label2.Caption = "Все записи введены"
End Sub
 
Private Sub Command2_Click()
d = 0
For i = 1 To 3
If Text4.Text = marshrut(i).nomer Then Text5 = marshrut(i).na4alo
If Text4.Text = marshrut(i).nomer Then Text6 = marshrut(i).konec
If Text4.Text <> marshrut(i).nomer Then d = d + 1
Next i
If d = 3 Then Text5.Text = "Нет такого маршрута"
If d = 3 Then Text6.Text = "Нет такого маршрута"
End Sub

If Text4.Text <> marshrut(i).nomer Then d = d + 1