Hi,

I am having a scenario where i am deleting a record in object A, it should delete int ObjectB too. so i have the triggers written to delete the records.

When i write the test class i get the following error

System.DmlException: Delete failed. First exception on row 0 with id 00UM0000001ItxKMAS; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, delete_app: execution of AfterDelete caused by: System.NullPointerException: Attempt to de-reference a null object Trigger.delete_app: line 8, column 1: []

Here are the triggers

trigger delete_app on Event (after delete) {
	List<Id> ev = new List<Id>();
	 List<Event> eventlist = new List<Event>();
	 List<Appointment__c> appoint = new List<Appointment__c>();
	 if (CApp_static.firstRunAppointment==false)
	 {
	 	CApp_static.firstRunAppointment=true;
	  for(Event e:Trigger.new)
    {
      
      ev.add(e.id);
      
    } 
    
    appoint=[select id from Appointment__c where eventid__c in :ev];
    if (appoint.size()>0)
    {
    delete appoint;
    }
	 }

}

trigger delete_event on Appointment__c (after delete) {
	
	List<Id> ev = new List<Id>();
	 List<Event> eventlist = new List<Event>();
	 List<Appointment__c> appoint = new List<Appointment__c>();
	 if (CApp_static.firstRunAppointment==false)
	 {
	 	CApp_static.firstRunAppointment=true;
	  for(Appointment__c e:Trigger.new)
    {
      
      ev.add(e.id);
      
    } 
 
    eventlist=[select id from Event where appointment_ID__c in :ev];
       if(eventlist.size()>0)
       {
    delete eventlist;
       }
	 }

}

 Here is the test class

public with sharing class TestCreateEvent_Create_App {
	static testMethod void CreateEvent_Create_App() 
    {
		Contact a = new Contact();
		
	 	a.FirstName = 'TestFirst Name';
        a.LastName='Test Last Name';
        a.MailingStreet='Test billing Street';
        a.MailingCity='Test Billing City';
        a.MailingState='Test Billing State';
        a.MailingCountry='Test Billing country';
        a.MailingPostalCode ='Test PostCode';
        insert a;
        
          
	
		String strstartdatetime='2011-12-25 10:00:00';
		String strenddatetime='2011-12-25 10:00:00';
		
		Event e= new Event();
		e.WhoId=a.id;
		e.subject  ='Test Event'  ;
		e.StartDateTime=datetime.valueof(strstartdatetime);
		e.EndDateTime=datetime.valueof(strenddatetime);
		e.Appointment_Type__c='Call';
		e.Status__c='Tentative';
		e.Create_Appointment__c=true;
		
		insert e;
		
		 strstartdatetime='2011-12-28 10:00:00';
		 strenddatetime='2011-12-28 10:00:00';
		
		Appointment__c ap= new Appointment__c();
		ap.subject__c= 'Test App';
		ap.client__c=a.id;
		ap.name='Test Name';
		ap.StartDateTime__c=datetime.valueof(strstartdatetime);
		ap.EndDateTime__c=datetime.valueof(strenddatetime);
		ap.Appointment_Type__c='Call';
		ap.Status__c='Confirmed';
		insert ap;
		
		
		List <event> even= new List<event>();
		even=[select id,Appointment_Type__c,subject,StartDateTime,EndDateTime from Event where id=:e.id];
		even[0].subject='Test Event update'	;
		update even;
		
		even=[select id,Appointment_Type__c,subject,StartDateTime,EndDateTime from Event where id=:e.id];
		if (even.size()>0)
		{
			delete even;
		}
		
		List <Appointment__c> apList= new List<Appointment__c>();
		apList=[select id,name,subject__c,Appointment_Type__c,EndDateTime__c,StartDateTime__c from Appointment__c where id=:ap.id];
		apList[0].Subject__c='Test App update';
		update apList;
		
		delete apList;
		
		
		
		
		}
}

 Any ideas where i am going wrong?