[Freesurfer] how to use mris_register?

Dear Mr,

When I execute mris_register to register one subject to a template., I have this message of error:

mris_register -1 s000/surf/lh.sphere avg_all_subjects_SD/lh.reg.template.tif sphere_reg treating target as a single subject's surface... $Id: mris_register.c,v 1.59 2011/03/02 00:04:33 nicks Exp $ $Id: mrisurf.c,v 1.693.2.2 2011/04/27 19:21:05 nicks Exp $ reading surface from s000_open_brain_sanlm_+TIR_normlalized/surf/lh.sphere... MRISread(s000_open_brain_sanlm_+TIR_normlalized/surf/lh.sphere): could not open file No such file or directory mris_register: could not read surface file s000/surf/lh.sphere No such file or directory

note that the file exist in the specifeid SUBJECT_DIR

Thank you for your help

Fatma