IDL syntax error caused by getenv(), a path error

Question

I am using exofast code in IDL, I set environment exactly as the developer describe it but when I ru the code for fitting I get this errors:

path = filepath('',root_dir=getenv('EXOFAST_PATH'),subdir=['examples','hat3'])
                            ^
% Syntax error.
  At: /usr/local/ITTVIS.IDL.v7.0.6.LINUX-TBE/idl706/EXOFASTv2/examples/hat3/fithat3.pro, Line 3

           prefix=path+'fitresults'+path_sep() +'HAT-3b.Torres.', maxsteps=maxsteps, $
                                              ^
% Syntax error.
  At: /usr/local/ITTVIS.IDL.v7.0.6.LINUX-TBE/idl706/EXOFASTv2/examples/hat3/fithat3.pro, Line 8

I don't know what is the problem in my environment. any help?