Installing rjb in centos

Hi all,

need a quick and urgent help

can anyone tell me how to install rbj in centos machine.
i have installed in with some errors and when i run my application it
gives this error

/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require’: no such file to load – rjbcore (LoadError)

i think it’s because i failed to install rbj sucessfully

can anyone help me

thankx in advance

cheers
sameera