For the subdomain i have used re-write rules
I have redirect [*].xyz.com to xyz.com/birthday.aspx?id=[*]
Consider user name is john
I have redirect "http://john.xyz.com" to "http://xyz.com/birthday.aspx?id=john"
It is redirecting properly and displays the page content,but due to redirection images and css is not working properly.
Copy and paste the following two urls on browser you will see the difference
1. Subdomin : http://john.xyz.com
2. Actual : http://xyz.com/birthday.aspx?id=john