I didn't use quotation marks in the file name. That was pasted from another forum wherein I was lazy about the formatting, so I used the quotes as erstwhile separators from the rest of the text.
glad you got it worked out, but the quotes I mentioned are in the original artivle you linked to:
(Tip: In the Save dialog box enter the name as “mymap.html†including the quotes to force Notepad to save the file with the extension .html and not .txt) (emphasis mine)
and I did change to Plain Text, just forgot to mention it.
