[Rd] developing a package: increase the number of functions

[Coster, Albart]

Dear list,
 
I am trying to develop a package. I used the function package.skeleton to make the directory tree of the package and then build and compiled the package as described (I hope). Now, I would like to increase the number of functions in the package without overwriting the existing package directory tree, so I put these new functions in the directory R of the tree. When I then build and install the package, I can not find the new functions, so apparently they are omitted from the installation. 
 
My question is: why does this occur? What should I do to get these new functions also installed? 
 
(I am using R 2.4.1)
 
Thanks in advance,
 
Albart Coster