Freemat portable help.

Hi all,
I am now using at freemat (yes, I have homework at numeric analysis)
and i try to use a simple function to understand how to add a new function to freemat.

I follow this guide:
Tutorial Make a Function
and I copy to test.m file that code:
function return_value=comb(n,r)
return_value=gamma(n+1)/(gamma(n-r+1)*gamma(r+1));

and save it at:
'E:\PortableAppsMenu\PortableApps\FreeMatPortable\Data'
I also add the this folder(and sub folder) with path tool like it say in the guide.

and then call to the function with this commend like in the example:
comb(7,3)

and it say this error massage:
Error: Undefined function or variable comb.

can you help me?

thanks for your time.
Tal.