if you want to prevent running multiple instance
of the same c# application then check the
following lines.It's sometime necessary to prevent
running multiple instances of the same application.

In wordpress there are some error free ways to add scripts and styles
in your custom  page in admin dashboard.If you don't follow these rules you
might see errors and it's not a good idea to declare script and styles without
this kind of some pre-defined actions.

in coding giving proper names to methods,classes,controls,
variables,others is neccessary and good programming practice.
think that a method name-show button click.

how to use private browsing?

If you don't want to save cookies and histories for certain activities
and for security purposes while browsing then Press CTRL + Shift + N,
which will launch new private browsing for Chrome, CTRL + Shift + P will
do it for Firefox and IE.

I have given many interviews on c#,asp.net jobs and
went through the questions.here i am posting,It may
help you -

It's possible to insert any kind of content in wordpress post or page using
short codes, but if you want to inject/modify content in post in more
advanced manner then there is a alternative is using filter

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.