Recovering information from TFitter

  Root
   I'm using Version 4.04/02 6 November 2005 on Linux machines at BNL.

  I make a TFitter with

    TVirtualFitter *minuit = TVirtualFitter::Fitter(0, 19);

  After the fit I try to recover the parmeters to save them to a file.   

     Double_t ParVal = minuit->GetParameter(i);
     Double_t ParErr = minuit->GetParError(i);

  works fine but if I try to get the parameter names via   char* parname = "";
   Double_t ParVal, ParErr, Vlow, Vhi;
  minuit->GetParameter(i,parname,ParVal,ParErr,Vlow,Vhi);

   I get a seg fault. Is it obvious what I'm doing wrong?

                    Bill Love