0x800a0005 Error when using OpenAsTextStream - vbscript

Question

My intention is to write every output line to a log file for archive purposes. Instead of writing to a file using OpenTextFile() and Write(), and then closing at the end of the script, I would like to write to the file as the script executes. If for whatever reason, the script is terminated before it has a chance to close the file, I worry I will lose those logs.
To achieve this, here is what I have attempted:
'Master Logs
Dim MasterLogFileName, MasterLogFile, MasterLogFileStream
Const ForAppending = 8
Const TristateUseDefault = 2
Function Write(text)
Wscript.StdOut.Write text
Set MasterLogFileStream = MasterLogFile.OpenAsTextStream(ForAppending, TristateUseDefault)
MasterLogFileStream.Write text
MasterLogFileStream.Close
End Function
'Create a Master Log file to write to
MasterLogFileName = "LogFile.log"
fso.CreateTextFile(MasterLogFileName)
Set MasterLogFile = fso.GetFile(MasterLogFileName)
Write("Test writing!")
Write("Test writing 2!")
However, I receive the following error:
0x800a005 - Microsoft VBScript runtime error: Invalid procedure call or argument
On this line:
Set MasterLogFileStream = MasterLogFile.OpenAsTextStream(ForAppending, TristateUseDefault)
When executing the Write() Function for the second time, using this line:
Write("Test writing 2!")

Answer 1

As specified by Lankymart and JosefZ, the reason this wasn't working was because I specified 2 for TristateUseDefault, instead of -2, as per the OpenAsTextStream method specifies.