{
   gROOT->ProcessLine(".L myvar.cpp");
   gROOT->ProcessLine(".L skim_athena.C");
   TChain *c1=new TChain("mytree");

   c1->Add("/rooms/sidious/higgs/alstone/em1trk/skimming/pass2_em1trk_tight_electron.root");

   skim_athena p1(c1);
   p1.analyze("pass2_em1trk_microskim.root");
}