Installing watir-webdriver on firefox

I try to install watir-webdriver on fedora linux. I ran this commands :

cat << EOF > /etc/yum.repos.d/ruby.repo
[ruby]
name=ruby for Fedora \$releasever - \$basearch - Base
baseurl=http://mirror.nl.ergo-project.org/repositories/custom-f13-ruby/x86_64/
failovermethod=priority
enabled=1
gpgcheck=0

[ruby-extra]
name=ruby extra for Fedora \$releasever - \$basearch - Base
baseurl=http://mirror.nl.ergo-project.org/repositories/feature-f13-ruby-1.9.1/x86_64/
failovermethod=priority
enabled=1
gpgcheck=0
EOF

yum -y --enablerepo=ruby,ruby-extra install ruby ruby-devel ruby-irb
gem update --system
gem install watir-webdriver

But When I ran the default script which is available on official website but I have the error

./firewatir:3:in `require': no such file to load -- wa开发者_如何学运维tir-webdriver (LoadError)
 from ./firewatir:3:in `<main>'

Can somebody help me ?

Since you've installed the library as a gem, you need to load Rubygems before watir-webdriver, i.e.:

require "rubygems"
require "watir-webdriver"