iam account and contact in account object iam having phonenumber=9999999999 and i need to update all contact mobilephone feild which are accosiated particular account i done with follwing code no error bt trigger not firing pls hlp....trigger accountupdatetrigger on account (after update) { if(trigger.isafter) { if(trigger.isupdate) { list<contact> lst = new list<contact>(); list <Account> a = [Select id,Name,phone, (Select id, Contact.FirstName,contact.LastName,contact.MobilePhone from Account.Contacts) From Account where phone ='99999999999']; for(Account acc1:a) { for(schema.Contact cn:acc1.Contacts) { // lst.add(cn); // } // if(cn.MobilePhone!=null && cn.MobilePhone==null) // { cn.MobilePhone ='99999999999'; update cn; } } } } }