Hi Team,

I have a two fields in opportunity object those are "Help(Picklist)" and "Description(Text)". If i select "help" pick list value is Manager and entering in the "description" field  is Test,that time automatic task has been creating along with opportunity name based on below trigger.But my problem is whenever i removed the specific values then that time also task is creating with Null values.How to include that logic in my existing trigger.And also If i change the Description value in the task object it should change the same in Opty field also.Please help us.

Trigger UpdateTask on Opportunity(after insert,after update){    
    List<Opportunity> listOpp = Trigger.new;
    List<Task> listTask = new List<Task>();    
    /* New Task */
    if(Trigger.isInsert){
        for(Opportunity opp:listOpp){    
           if(opp.Help__c != null){
                Task t = new Task();
                t.OwnerId = opp.OwnerId;
                t.WhatId = opp.Id;
                t.Subject ='Help' + ': ' +opp.Help__c + ': '  + opp.Name; 
                t.ActivityDate = System.Today()+7;  
                t.Description = opp.Description__c;
                t.Status = 'In Progress';
                t.Priority = 'Normal';
                listTask.add(t);
            } 
        }
    }   
    // UPDATE the Same Task 
     if(Trigger.isUpdate){
        Set<Id> setOppId = new Set<Id>();
         Map<Id,Opportunity> oldOppMap = Trigger.oldmap;
        for(Opportunity opp:listOpp){
            if(Opp.Help__c != oldOppMap.get(opp.Id).Help__c || Opp.Description__c!= oldOppMap.get(opp.Id).Description__c){
            Task t = new Task();
            t.WhatId = opp.Id;   
            t.Subject = 'Help' + ': ' +opp.Help__c + ': '  + opp.Name; 
            t.Description = opp.Description__c;  
            t.ActivityDate = System.Today()+7;
            listTask.add(t);
         }
        }
    } 
        insert listTask;
}

Thanks in Advance