void read(TTree &tree,int entry)
{
    int event;
    tree.SetBranchAddress("event_spill",&event);
    if( tree.GetEntry(entry)<0 )
        printf("Failed to read entry!\n");
    else
        printf("For the tree entry %d event number is %d\n",entry,event);
}

void r(void)
{
    TFile f("1.root");
    if( !f.IsOpen() )
    {
        printf("File was not opened!\n");
        return;
    }

    TTree *tree = f.Get("Dtree");
    if( tree==NULL )
    {
        printf("No tree!\n");
        return;
    }
    
    printf("The TTree::Scan() gives:\n");
    tree->Scan("event_spill");

    printf("And my read is:\n");
    read(*tree,0);
    read(*tree,1);
}