When to use Request.UrlReferrer and when Request.ServerVariables["HTTP_REFERER"]?

Question

Both returns the incoming url, Just to know When to use Request.UrlReferrer and when Request.ServerVariables["HTTP_REFERER"] and why?

Currently, in one of my application Urlreferrer is working in my local machine but its not working when went live?

Additionally, its most appreciable if anyone can guide any alternative of both Urlreferrer and HTTP_REFERRER?

Answer 1

Answering to last question. Request.UrlReferrer returns an Uri object, so if UrlReferrer has bad format then you get an exception. It seems strange, but some times I have got it. HTTP_REFERER is a string.