Troubles compiling samples on VC++ 6 SP5

Hi all,

I am trying to compile the samples in the latest stable libnet version,
more specifically the icmp timestamp sample.

When trying to do so, I can compile just fine, but I get linking errors.
And I don't know how to solve those, any help would be greatly appreciated.

What I have done so far is install VC++ sp5; install the winpcap development
library; install the 2003 platform SDK and build the libnet.dll & libnet.lib
(I had to edit the libnet_prand.c file (the libnet_get_prand function) to
make this work, otherwise I got linking errors again).

Then I added the necessary folders to the lib & include directories according
to the readme.txt in the win32 folder. 
Finally I added the libnet\include directory to the list of include directories.

Now when I try to build the icmp timestamp sample I add the libnet.lib file
to the project, and try to built which gives me the following output.

--------------------Configuration: icmp_timestamp - Win32 Debug--------------------
Compiling...
icmp_timestamp.c
Linking...
icmp_timestamp.obj : error LNK2001: unresolved external symbol _optarg
icmp_timestamp.obj : error LNK2001: unresolved external symbol _getopt
Debug/icmp_timestamp.exe : fatal error LNK1120: 2 unresolved externals
Error executing link.exe.

icmp_timestamp.exe - 3 error(s), 0 warning(s)

Any help would be wonderful.

Thanks
Kim