[Orgmode] Babel - simple getting started problem

[Graham Smith]

I know I must be missing the obvious here, but why can't I get babel+R
to calculate a mean. See below

Many thanks,

Graham

* test
#+srcname:trial
#+begin_src R
x<-c(4,5,6,7,8,9)
#+end_src

#+resname: trial
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |


* meantest
#+begin_src R
mean(trial)
#+end_src

#+resname:

error in buffer "source block produced no output"

* meantest2
#+begin_src R
mean(x)
#+end_src

#+resname:

error in buffer "source block produced no output"