Hmm it seems to work for me and everyone else, heres the case statement.
$File = @ScriptDir & "\Point Of Sale\Logs\" & _DateToNumber(GUICtrlRead($Date1)) & "\" & GUICtrlRead($ListBox) & ".txt"
Dim $FArray
$String = ""
$LISTGUI = GUICreate(" ", 389, 453, -1, -1, _
BitOR($WS_SYSMENU, $WS_CAPTION, $WS_POPUP, $WS_POPUPWINDOW, $WS_BORDER, $WS_CLIPSIBLINGS))
$Button1s = GUICtrlCreateButton("Close this transaction", 8, 424, 371, 25, 0)
$List10 = GUICtrlCreateList("", 0, 0, 385, 422)
If $FullScreen = True Then _SetParent($LISTGUI, "Point Of Sale")
_FileReadToArray($File, $FArray)
For $i = 1 To $FArray[0] - 1
_GUICtrlListBox_AddString($List10, $FArray[$i])
Next
WinSetTitle($LISTGUI, "", GUICtrlRead($ListBox) & " Log")
If $FullScreen = True Then
GUISetState(@SW_HIDE, $TransGUI)
GUISetState(@SW_HIDE, $Form1_1)
EndIf
GUISetState(@SW_SHOW, $LISTGUI)