trouble installing RCurl

Hi, all
I got following errors when I tried to install "RCurl" in Ubuntu. 
my R version is 

na at ubuntu:~$ R --version
R version 2.15.0 (2012-03-30)
Copyright (C) 2012 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform: i686-pc-linux-gnu (32-bit)

thanks in advance


* installing *source* package ?RCurl? ...
** package ?RCurl? successfully unpacked and MD5 sums checked
checking for curl-config... no
Cannot find curl-config
ERROR: configuration failed for package ?RCurl?
* removing ?/home/na/R/i686-pc-linux-gnu-library/2.15/RCurl?

The downloaded source packages are in
        ?/tmp/RtmpTdSf9C/downloaded_packages?
Warning message:
In install.packages(RCurl) :
  installation of package ?RCurl? had non-zero exit status

na at ubuntu:~/R/i686-pc-linux-gnu-library/2.15$ R CMD INSTALL
RCurl_1.91-1.tar.gz 
* installing to library ?/home/na/R/i686-pc-linux-gnu-library/2.15?
* installing *source* package ?RCurl? ...
** package ?RCurl? successfully unpacked and MD5 sums checked
checking for curl-config... no
Cannot find curl-config
ERROR: configuration failed for package ?RCurl?
* removing ?/home/na/R/i686-pc-linux-gnu-library/2.15/RCurl?


--
View this message in context: http://r.789695.n4.nabble.com/trouble-installing-RCurl-tp4631139.html
Sent from the R help mailing list archive at Nabble.com.