Problem with nc_read.m

[layeghi2001]

Hello friends.
I have problem with extract_bath.m. when I run it in matlab R2009a, this message apears:

??? Error file: nc_read.m : line 91 column : 10
Expression or statement is incorrect-- possibly unbalanced ( , [ , or [.
Error in ==> X_etopo5 at 37
X= nc_read(Fname,'topo_lon');
Error in ==> extract_bath at 44
[lon,lat,h]=X_etopo5(Llon,Rlon,Blat,Tlat,Bname);

can anyone help me why this problem apears? and what is its solution?