Using a variable to name a new text file - vbscript

Question

I have a small script that I want to find the computers name, and create a text file in the flash drive the script will run from named after the PC's name.
So far I can pull the name into a variable, and create a text file with a string literal argument. but If I try to pass the name into GetFileName and GetAbsolutePathName calls it either gives me an error or gives the file a blank name.
Edit: I have updated the code to the full code. The program is intended to get the Windows license keys on all the computers in the labs I manage for easy reference. I apologize if the issue is simple, this is my first script I have written, and I feel like it is something I just seem to be missing.
The code in question:
Set WshShell = CreateObject("WScript.Shell")
ConvertToKey(WshShell.RegRead("HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\DigitalProductId"))
Set wshShell = CreateObject( "WScript.Shell" )
strComputerName = wshShell.ExpandEnvironmentStrings( "%COMPUTERNAME%" )
Function ConvertToKey(Key)
Const KeyOffset = 52
i = 28
Chars = "BCDFGHJKMPQRTVWXY2346789"
Do
Cur = 0
x = 14
Do
Cur = Cur * 256
Cur = Key(x + KeyOffset) + Cur
Key(x + KeyOffset) = (Cur \ 24) And 255
Cur = Cur Mod 24
x = x - 1
Loop While x >= 0
i = i - 1
KeyOutput = Mid(Chars, Cur + 1, 1) & KeyOutput
If (((29 - i) Mod 6) = 0) And (i <> -1) Then
i = i - 1
KeyOutput = "-" & KeyOutput
End If
Loop While i >= 0
ConvertToKey = KeyOutput
Dim filesys, filetxt, getname, path
Set filesys = CreateObject("Scripting.FileSystemObject")
Set filetxt = filesys.CreateTextFile("I:\"& strComputerName & ".txt", True)
path = filesys.GetAbsolutePathName("I:\"& strComputerName & ".txt")
getname = filesys.GetFileName(path)
filetxt.WriteLine(KeyOutPut)
filetxt.Close
End Function
The result is a text file named ".txt" in the correct location.

Answer 1

You must pass strComputerName into the function, and preface the call with the Call keyword.