read multiple sheets of excel data into R

Hi all,
  I tried to use the package "XLConnect" to read excel data into R.  I got
the following error message:

Error : .onLoad failed in loadNamespace() for 'rJava', details:
  call: fun(libname, pkgname)
  error: No CurrentVersion entry in Software/JavaSoft registry! Try
re-installing Java and make sure R and Java have matching
architectures.


  I tried read.xls and got the following error  message:

library(gdata)> one <- read.xls ("one.xlsx", sheet=1)Error in findPerl(verbose = verbose) :

perl executable not found. Use perl= argument to specify the correct
path.Error in file.exists(tfn) : invalid 'file' argument


  Can anyone give me some input on this?
  Thanks.
    Hanna