event firing in a class

Question

hello everyone in a class i have some properties. 4 of  them are static props. fifth of them is not public and in set method of the fifth one i want to fire an event. and parameters of the event the other four props.  event code in the set  method is like this;
if(value= =true)   // if the property gets the true event will be fired
{
if(event!=null)
{
event(1 static prop,2 statik prop.. 4 statik prop)
}
}
i assigned the value of true in c#. i use breakpoint in c# to debug. when te term comes to code
event(1 static prop,2 statik prop.. 4 statik prop) i control the properties values thy are right but  whn firing i get error "object reference not to set instance of an object". in the event parameters i use public variables of  properties. and if i write "if (evnt!=null)"  if block doesnt work but if i write if(event==null) this block works.
can anyone help please

nkay · Answer

really thanks friends. the problem is the point two of you say. i mean you are right. however i cannot catcht event from the asp.net application. in one solution  i have 4 projects. one is class liibrarry only cointains events. one is asp.net project, another one is webservice, the other one is windows aplication project.  in class project which only contains events, i rise event in the event class with methods  as Alistaire thrussell said. in win application i use eventRaisermethod to fire the event. but i cannot catch it from the asp.net project. in asp project i wrote this line of code to cath event;
in page load event     class.event +=new class.delegate(method);
void method() {......}
but i cannot cath :(
in short, i want to use events in a class library project, fire them in winapp project, and cacth thm from asp.net project. or again using event project and to fire events from asp project and catcth them in winapp project.
really thanks friends fro your ideas and help

Alistair Thrussell · Answer

Without a bit more code we can only assume the event has not been initialized. You need both an event and a delegate to have a public event that can be trapped by a class calling your class.
someClass
{
public delegate void someEvent (String Parameter);
public event someEvent SomeEvent_SomeThingHappended;
public void MethodThatRaisesEvent()
{
someEvent(SomeParameter);
}
}

Alan · Answer

Are you sure that you've assigned a new instance of the appropriate delegate type to your 'event' variable? If you haven't then it will always be null.