Error When trying to build crosstool-ng.

Hi,

     I am trying to build crosstool-ng using the command ct-ng build. I am getting the below error.Please help me to resolve this issue.

[INFO ] Performing some trivial sanity checks
[INFO ] Build started 20130111.112707
[INFO ] Building environment variables
[ERROR] Missing: 'i686-pc-linux-gnu-g++' or 'i686-pc-linux-gnu-g++' or 'g++' : either needed!
[ERROR]
[ERROR] >>
[ERROR] >> Build failed in step '(top-level)'
[ERROR] >>
[ERROR] >> Error happened in: CT_Abort[scripts/functions@327]
[ERROR] >> called from: CT_TestAndAbort[scripts/functions@347]
[ERROR] >> called from: main[scripts/crosstool-NG.sh@446]
[ERROR] >>
[ERROR] >> For more info on this error, look at the file: 'build.log'
[ERROR] >> There is a list of known issues, some with workarounds, in:
[ERROR] >> '/opt/crosstool-ng-1.17.0/share/doc/crosstool-ng/ct-ng.1.17.0/B - Known issues.txt'
[ERROR]
[ERROR] (elapsed: 0:01.29)
[00:02] / make: *** [build] Error 1