void query()
{
    int i,j,k,l;
    char swap_[20];
    for(i=0; i<counter; i++)
    {
        lowercase(person[i].fname);
        lowercase(person[i].lname);
    }
    for (i=0 ; i < counter; i++)
    {
        for (j=0; j < counter-1; j++)
        {
            if (strcmp(person[j].lname,person[j+1].lname)>0)
            {
                strcpy(swap_,person[j].lname);
                strcpy(person[j].lname,person[j+1].lname);
                strcpy(person[j+1].lname,swap_);

                strcpy(swap_,person[j].fname);
                strcpy(person[j].fname,person[j+1].fname);
                strcpy(person[j+1].fname,swap_);

                strcpy(swap_,person[j].address);
                strcpy(person[j].address,person[j+1].address);
                strcpy(person[j+1].address,swap_);

                strcpy(swap_,person[j].city);
                strcpy(person[j].city,person[j+1].city);
                strcpy(person[j+1].city,swap_);

                strcpy(swap_,person[j].number);
                strcpy(person[j].number,person[j+1].number);
                strcpy(person[j+1].number,swap_);
            }
            else if(strcmp(person[j].lname,person[j+1].lname)==0)
            {
              if (strcmp(person[j].fname,person[j+1].fname)>0)
            {
                strcpy(swap_,person[j].lname);
                strcpy(person[j].lname,person[j+1].lname);
                strcpy(person[j+1].lname,swap_);

                strcpy(swap_,person[j].fname);
                strcpy(person[j].fname,person[j+1].fname);
                strcpy(person[j+1].fname,swap_);

                strcpy(swap_,person[j].address);
                strcpy(person[j].address,person[j+1].address);
                strcpy(person[j+1].address,swap_);

                strcpy(swap_,person[j].city);
                strcpy(person[j].city,person[j+1].city);
                strcpy(person[j+1].city,swap_);

                strcpy(swap_,person[j].number);
                strcpy(person[j].number,person[j+1].number);
                strcpy(person[j+1].number,swap_);
            }
             else if(strcmp(person[j].fname,person[j+1].fname)==0)
             {
                 if(strcmp(person[j].number,person[j+1].number)>0)
                 {
                     strcpy(swap_,person[j].lname);
                strcpy(person[j].lname,person[j+1].lname);
                strcpy(person[j+1].lname,swap_);

                strcpy(swap_,person[j].fname);
                strcpy(person[j].fname,person[j+1].fname);
                strcpy(person[j+1].fname,swap_);

                strcpy(swap_,person[j].address);
                strcpy(person[j].address,person[j+1].address);
                strcpy(person[j+1].address,swap_);

                strcpy(swap_,person[j].city);
                strcpy(person[j].city,person[j+1].city);
                strcpy(person[j+1].city,swap_);

                strcpy(swap_,person[j].number);
                strcpy(person[j].number,person[j+1].number);
                strcpy(person[j+1].number,swap_);
                 }
             }
            }
            else
                continue;
        }
    }
    system("cls");
    for (i=0 ; i <counter; i++)
        printf("%d)\nfirst name: %s\nlast name: %s\nAddress: %s\nCity: %s\nNumber: %s\n",i+1,person[i].fname,person[i].lname,person[i].address,person[i].city,person[i].number);
}