[ns] Patch file error

[#LIN ZHILING#]

 
I have successfully applied the patch thing file in ns-lib.tcl and Makefile.in.
The only problem nowis with ns-default.tcl. 
when the command patch -bNp1 ns-default.tcl patch_ns-default.tcl 
run, an error occur saying 
HUNK #1 FAILED at 79
1 out of 1 hunk FAILED -- saving rejects to file ns-default.tcl.rej
 
Can anyone enlighten me in this area.
Thank You