Hi,

>I was thinking of Mastering ASP.NET & VB.NET for Internet applications. But all the web sites seem to be using PHP.

In my experience, most internet applications are in fact intranet applications. If anything is visible at all, it's usually the login screen. In other words, it's hard to tell the demand of a particular web technology just from browsing the internet.

In any case, there's MUCH more to internet development than just PHP vs. ASP.NET. For instance, you have to deal with web servers, JavaScript, XML, HTML, CSS, SQL, etc. plus a whole set of knowledge about using sessions, cookies, testing, security, and much more. If you truly master web applications in one language it's not that difficult to write code in another language.