Using a Data file

Ok, how do i use a dat file? I want the dat file to collect the highest amount of "sales" in my project. I know i gotta use a Do while loop, but i'm not fulent with that. Basicly my Dat file looks like this:


Dailysales.dat
101
10.00
5.00
124.75
-1
102
32.50
67.00
4.95
-1
101
43.00
25.00
-1
103
27.75
34.65
2.00
-1

That it for the dat file, but 101 , 102 ,103 are ID numbers fro Joe,Mary and Ted.

Thanks for any help.

Something like this:

VB Code:

Dim intFFN As Integer
    Dim dblAmount As Double
    Dim strBuffer As String
    
    intFFN = FreeFile
    
    Open "C:\Dailysales.dat" For Input As #intFFN
    
    Do Until EOF(intFFN)
        Line Input #intFFN, strBuffer
        
        If dblAmount < CDbl(strBuffer) Then dblAmount = CDbl(strBuffer)
    Loop
    
    Close #intFFN
    
    MsgBox "The highest amount is " & dblAmount