asp need help please

if i want use counter to count the number of visitor view to my web site how am i going to work with.

here some code of that i write but once the same user refresh it will increment. all i want is once the user visit no matter how many times it refresh consider + 1. when the user close the site and review the counter need to + 1 again.


<%
Set FS=Server.CreateObject("Scripting.FileSystemObject")
Set RS=FS.OpenTextFile(Server.MapPath("counter.txt"), 1, False)
fcount=RS.ReadLine
RS.Close

fcount=fcount+1

Set RS=FS.OpenTextFile(Server.MapPath("counter.txt"), 2, False)
RS.Write fcount
RS.Close

Set RS=Nothing
Set FS=Nothing

%>