METHOD:  FileSystemObject.GetExtensionName

Implemented in version 2.0
 
object.GetExtensionName(path)

Used to return a string containing the extension name of the last component in a supplied path. If no component matches the supplied path string the GetExtensionName method will return an empty string.

Code:
<%
dim filesys, a
Set filesys = CreateObject("Scripting.FileSystemObject")
filesys.CreateTextFile "c:\DevGuru\website\VBScript.txt", True
a = filesys.GetExtensionName("c:\DevGuru\website\VBScript.txt")
Response.Write (a)
%>

 
Output:
"txt"