How To Check If A File Is Empty?

Here is part of my code:

If fs.FileExists(Server.MapPath("filename.htm") Then
set f=fs.OpenTextFile(Server.MapPath("filename.htm"))
If f.ReadLine <> "" Then

First, I check to see if the file exists. If so, then I open the file for reading. Then, I read the first line to see if it equals "".

The problem here, though, is that if the file is empty, I'll get a "Input past end of file" error. So, how do I check to see if it's empty without reading the lines?