关于结构体指针删除问题

void Cancle(LinkList &l)
    {
        ClientInfo *CI=new ClientInfo;
        ClientInfo *p=new ClientInfo;
        ClientInfo *q=new ClientInfo;
        CI=l.cFirst->next;
        int CardNum;
        char*PlaneNum=new char;
        cout<<"===========退票============"<<endl;
        cout<<"请输入您的证件号：";
        cin>>CardNum;
        while(1)
        {
            if(CI->CardNum!=CardNum&&CI!=NULL)
            {
                CI=CI->next;
            }
            if(CI==NULL)
            {
                cout<<"证件号输入有误，请重新输入:";
                CI=l.cFirst->next;
                cin>>CardNum;
            }
            else
            {
                break;
            }
        }
        cout<<"您的所有订单信息如下："<<endl;
        /*@@@显示该客户所有订单信息@@@*/
        while(CI!=NULL)
        {
            if(CI->CardNum==CardNum)
            {   
                cout<<"======================="<<endl;
                cout<<"姓名：    "<<CI->name<<endl;
                cout<<"订单号：  "<<CI->OrderNum<<endl;
                cout<<"证件号：  "<<CI->CardNum<<endl;
                cout<<"航班号：  "<<CI->PlaneNum<<endl;
                cout<<"======================="<<endl;
                CI=CI->next;
            }
            else
            {
                CI=CI->next;
            }
           
        }
        CI=l.cFirst->next;
        cout<<"请输入您想要退票的航班号：";
        fflush(stdin);
        gets(PlaneNum);
        while(1)
        {
            if(strcmp(CI->PlaneNum,PlaneNum)!=0&&CI!=NULL)
            {
                CI=CI->next;
            }
            if(CI==NULL)
            {
                cout<<"航班号输入有误，请重新输入:";
                CI=l.cFirst->next;
                fflush(stdin);
                gets(PlaneNum);
            }
            else
            {
                break;
            }
        }
        //销毁结点
        q=CI=l.cFirst->next;
        while(strcmp(CI->PlaneNum,PlaneNum)!=0&&CI!=NULL)
        {
            p=CI;
            CI=CI->next;
        }
        if(strcmp(CI->PlaneNum,PlaneNum)==0)
        {
        
                p->next=CI->next;
                delete CI;
                CI=NULL;
                cout<<"退票成功！";
        
        }
        ofstream fout("航班预订情况.txt");
        if(!fout)
        {
            cout<<"文件打开失败！";
            exit(-1);
        }
        while(q!=NULL)
        {
            cout<<"111";
            cout<<q->PlaneNum;
            cout<<"222";
            fout<<q->PlaneNum<<" ";
            fout<<q->name<<" "<<q->OrderNum<<" "<<endl;
            q=q->next;
        }
        fout.close();
   
    }