vb.net counting

Please help
This program is to check if the unit is pass or fail
unit 1 all step pass = pass
unit 2 one of the step is fail = fail
Unit 3 all step pass = pass

1. user browse txt file display in textbox
2. hit "run button"
3. count unit pass or fail.

I want the software reading the text until detect the word "unit" then start counting how many "pass".
If 3 "pass" means unit 1 = pass . then count again if detect the word "unit".

Text box info :

name:bla bla
date:28/2/2013
time:00:12

Unit Step result
Unit 1 001 pass
002 pass
003 pass


unit 2 001 fail
002 pass
003 pass

unit 3 001 pass
002 pass
003 pass

my coding

 Dim wordString As String
        wordString = Me.TextBox1.Text.ToString()
        Dim wrdCnt As MatchCollection = Regex.Matches(wordString, "FAIL")
        Dim wrdCnt2 As MatchCollection = Regex.Matches(wordString, "PASS")
        Dim Value1 = wrdCnt.Count.ToString()
        Dim value2 = wrdCnt2.Count.ToString()

        result1.Text = value2
        result2.Text = Value1 

above coding only can count how many pass or fail inside the text file

but i want calculate each unit is pass of fail.

please help.