I am trying to refer the element(`listname.contactid`) from the list but I am getting error:

> 
> Variable doesn't exist error
> 
> 
> 

However I am getting the entire list when I just use list name. 

I know I that I am doing something wrong. 

Can someone please help me solve this guide me to learn the cause of the this. 
Thank you. Code is given below.

---

```
trigger dlrs_CampaignMemberTrigger on CampaignMember(after delete, after insert) {

    list campaignlist = new list();
    set cmpId = new set();
    if (trigger.isDelete) { //system.debug(trigger.old); 
        for (CampaignMember campMem: trigger.old) {
            CampaignMember cpm = new CampaignMember();
            cpm.CampaignId = campMem.CampaignId;
            cpm.contactid = campmem.contactid;
            cpm.LeadId = campmem.LeadId;
            campaignlist.add(cpm); //error Method does not exist or incorrect signature: void add(CampaignMember) from the type CampaignMember 
            cmpId.add(campMem.CampaignId);
            system.debug(campaignlist);
            system.debug(campaignlist.contactid); //---- error Variable doesn't exist: contactid 
        }
        campaign[] campname = [select name from campaign where Id in: cmpId];
        system.debug(campname);

    }
}

```