Script that checks a file keeps returning same data even if file was changed?

I have a script that opens up a text file that contains information about a target hour, minute, and second. When I first run the script, the time showed is the time in the text file. However, when I put it in a loop and have it reload my file data, even if I change the txt file, the script still returns the old value.

#include <file.au3>
#include <array.au3>

global $target_min, $target_sec

while 1
    rereadconfig()
WEnd

Func rereadconfig()
    $file = "Z:\Documents\config.txt"
    $filehandle=FileOpen($file, 0)
    if ($filehandle=-1) Then
        MsgBox(0,"Missing Config File", "'config.txt' not present in this programs directory. Program will quit.")
        Exit
    EndIf

    local $config[2]
    For $i = 1 to _FileCountLines($file) step 3
        $config[($i/3)] = FileReadLine($file, ($i+1))
    Next
    FileClose($file)

    msgbox(0,"",$config[0]) 

    $target_min = $config[0]
    $target_sec = $config[1]

EndFunc

And my text file is 

target minute
54

target second
0

The for loop I used a step of 3 to only read in the 2nd and 5th lines.

Here is what happens when I run this script:

Run

msgbox pops up reading 54

at that point i change the 54 in the text file to say 25 and press save

then i press ok on the message box

msgbox pops up reading 54 again, even though the text file reads 25.

Is there something I'm missing? I closed the file each time it queries the text file, unless autoit stores a copy of the text file in the buffer.

Any help would be appreciated. Thanks!