command objects use parameters for passing values
to sql statements for type cheking,validation,guarding
against SQL injection attacks,etc.so its a good practice
to use command parameters to sql statements.

It's required that you configure your joomla SMTP settings so that joomla is able to send
email when user registered or different mailing functions works for other components and modules
like k2, CB....
In this post i show how to configure joomla 2.5/3 smtp settings properly.

namespaces is a old concept in c# programming.both
java and c# uses this concept.a namespace is act like
a 'wrapper' around one or many elements which gives
them uniqueness.

you can use online paypal buy button in your page
for receiving online paypal payment.when users click
this buy button they will enter in payment page
for payment.

master pages creates a common look in your application.
if we think about the header and footer in our pages,we
create these header and footer in every aspx pages.this
method has disadvantages.if there were any custom page
which dynamically adds header and footer then would be
good.