Prevent illegal hotlinking This station picture method

The main idea is to use Request.ServerVariables collection to get Http_referrer, and then based on the value of this variable to determine whether the link from the outside, block illegal links.
First, we need to make the following reference to the picture:

For getimg.asp We do the following:
<%
Option Explicit
Dim Server_link,filepath
Server_link=request. ServerVariables ("Http_referrer")
Server_link=mid (Server_link,instr (Server_link, ".") +1)
Server_link=left (Server_link,instr (Server_link, "/")-1)
If server_link= "Code-123.com" Then
Filepath= "Picture folder Address" + request.querystring ("FName")
Else
filepath= "/images/illegal link. jpg"
End If
Response.Redirect (FilePath)
%>
Can realize the hotlinking effect.