hbcontract2002:I have multiple websites which running under Default Web Site on IIS under development server.
No, you have multiple applications running under the default web site.
hbcontract2002:My guess is we have to change the localhost to servername ...
Your guess is correct. But it's in the code, not in the server, so you just need to find all the occurrences of "127.0.0.1" and change them to www.abc.com in your code. Next time you develop, take a look at relative links instead of absolute links.
Jeff