Response.Write("");
we can display alert box from asp.net code-behind that is 1. ScriptManager.RegisterStartupScript(this,GetType(),"alertmsg","alert('hahahahah');",true);
IN order to Show MessageBox you can add the MessageBox Class in your page and use MessageBox.Show("Your Message");
Access specifiers ::
The access specifier determines how accessible the field is to code in other classes. Access ranges from totally accessible to totally inaccessible. You can optionally declare a field with an access specifier keyword: public, private, or protected.
Access Modifiers ::
You can optionally declare a field with a modifier keyword: final or volatile and/or static and/or transient, abstract, etc.