TUTORIAL: ServerVariables of ASP

• How to find the physical path of virtual site
• Display Server variable
• IP Address of the remote user
• Browser Type of the user
• Show Message depending on User language
• Make a delay before or while loading
• How to keep track of Visitors
• How to redirect the visitor
• How to pass variables from Page to Page
• How to force a User to enter password
• How to display the number of users currently online

Physical Path
The physical path of this virtual web site is <%= Server.MapPath("\")%>
Outputs : The physical path of this virtual web site is C:\Inetpub\wwwroot

Server Variables

<% For Each Item In Request.ServerVariables %>
<% = Item %> = <% = Request.ServerVariables(Item)%>
<% Next %> 

HTML:

IP Address
My IP address is <%=Request.ServerVariables("REMOTE_ADDR")%>
Outputs : My IP address is 173.34.34.6

Browser type of User
The Browser type is <%=Request.ServerVariables("HTTP_USER_AGENT")%>
Outputs : The Browser type is <%=Request.ServerVariables("HTTP_USER_AGENT")%>

Show Message depending on User language

<% language = Request.ServerVariables("HTTP_ACCEPT_LANGUAGE")
If language = "en" Then %>"
<% Else %>
<% End If %>

HTML:

Page Delay
2 second delay before the rest of the code on the page is executed.

<%
' Define a small function
Sub TLdelaySec(DelaySeconds)
SecCount = 0
Sec2 = 0
While SecCount 
Sec1 = Second(Time())
If Sec1  Sec2 Then
Sec2 = Second(Time())
SecCount = SecCount + 1
End If
Wend
End Sub
%>

HTML:

Call the above function as follows to make a 2 second delay
<% TLdelaySec(2) %>

How to log visitor Visits
1. Create an ascii file with the filename as current systemtime
2. Get the visitors IP Address
3. Check if the referring page exists

<%
' Lets get the date right so we can name the log file
LogFileDate = Date
LogFileName = ""
	 If Month(LogFileDate) 
LogFileName = "0"
End If
	 LogFileName = LogFileName & Month(LogFileDate)
	 If Day(LogFileDate) 
LogFileName = LogFileName & "0"
End If


' Now place it in the proper directory and deal with it
LogFileName = "/tracking/" & LogFileName & Day(LogFileDate) & Year(LogFileDate) & ".log"
Set fs = CreateObject("Scripting.FileSystemObject")
' Make sure we can APPEND to the file - thats what the 8 is for
Set a = fs.OpenTextFile(server.mappath(LogFileName), 8, True, False)
	' If there is NO REFERER Then Skip this mess
if Request.ServerVariables("HTTP_REFERER") 
Request.ServerVariables("HTTP_REFERER") = 0
Else
' If there is a Referer then write the information to the log
a.Wriste("Referer: " & Request.ServerVariables("HTTP_REFERER"))
a.Write(" IP Address: " & Request.ServerVariables("REMOTE_ADDR")) & VBcrlf
End if
' Now its recorded adn ready for the next visitor
%>

HTML:

How to redirec visitor
Using the Redirect method to redirect the browser to another URL.
Firstly of all turn on buffering.
Note : This statement must appear before the tag.
<% Response.Buffer = True %>
Then you can redirect the browser by doing this.
<% Response.Redirect "somepage.asp" %>

How to pass variable from page to page

<% For each item in Request.Form %>
" Type = "Hidden" VALUE = "<% = Server.HTMLEncode(Request.Form(item)) %>">
<% next %>

HTML:

How to force password request
<%
Response.Status="401 Not Authorized"
Response.End
%>


In brief, by placing this code at the Top of the page, you will force the dialog box to appear.
If the proper information is not entered, they will not be allowed to view the document.
Capture the User Name that was entered by using the following line of code in your document:
<%=Request.ServerVariables("Logon_User")>


How to display the number of users on line
Code to be placed in global.asa

<script language=VBScript runat=Server>
Sub Application_OnStart	
Application("useronline") = 0
End Sub

Sub Application_OnEnd	
	' Do Nothing
End SubSub
	Session_OnStart	
	Session.Timeout = 20	
	'---Lock the Application variable before updating	
	Application.Lock
		Application("useronline") = Application("useronline") + 1	
	Application.Unlock
End Sub
	Sub Session_OnEnd	
	Application.Lock	
	Application("useronline") = Application("useronline") - 1	
	Application.Unlock
End Sub
</script>

HTML:

Code to be placed in the asp file to diaplay the actual number of users currently online
Number of User OnLine now : <%=Application("useronline")%>