you will need to access html elements from asp.net
code behind file.i show you how to access widely used
html textarea element from code behind file -

you may read many article in web about how to make a page
not to be cached using meta tags like that in the head
section -

you may want to get the asp.net control's or html element's
id when clicked or other events fired for that element.
It can be done in many ways using jquery or simple javascript.

The abstract class indicates that a class may be used
as a base class for other classes and is not instantiable.

If you want to run your software with same width and
height as your monitor's width and height then
implement the following technique in your application-

It's a very common requirement to show hint in textbox when empty
and when textbox gets focus hint goes away.now a days many websites
implemented showing hint.there are many ways to do that by jquery.