[gmx-users] Problems with g_hbond

[Tanos]

      Hi users,
       I am facing a little problem with g_hbond. I am runnig the 
comands like showed bellow but GROMACS is sending back the error message 
showed in the sequence bellow. What am I doing wrong ????? Could someone 
help-me  ?????

"trjconv -f protein_md.trr -o protein_md.xtc"
"g_hbond -f protein_md.xtc -s protein_md.tpr -hnum protein_hnum.xvg"

Error mesage:

"Unknown argument: -hnum
Unknown argument: protein_hnum.xvg
Fatal error: Program g_hbond halted"