[R] Function call within a function.

[John Kane]

I am trying to call a funtion within another function
and I clearly am misunderstanding what I should do. 
Below is a simple example.
I know lstfun works on its own but I cannot seem to
figure out how to get it to work within ukn. Basically
I need to create the variable "nts". I have probably
missed something simple in the Intro or FAQ.

Any help would be much appreciated.

EXAMPLE
-------------------------------------------------------------------------------
# create data.frame
cata <- c( 1,1,6,1,1,4)
catb <- c( 1,2,3,4,5,6)
id <- c('a', 'b', 'b', 'a', 'a', 'b')
dd1  <-  data.frame(id, cata,catb)

# function to create list from data.frame
lstfun  <- function(file, alpha , beta ) {
cda  <-  subset(file, file[,1] == alpha)
cdb  <-  subset (file, file[,1]== beta)
list1 <- list(cda,cdb)
}

# funtion to operate on list
ukn  <-  function(file, alpha, beta, nam1){
aa  <- alpha
bb  <- beta
myfile  <- file
nts <- lstfun(myfile, aa, bb)
mysum <- nam1[,3]*5
return(mysum)
}

results <- ukn(dd1, "a", "b", nts$cda)