Simple steps to get ruby 1.9.3 for calabash on mac osx 10.7

I did face this problem of getting ruby 1.9.3 on mac osx 10.7
Then I realized I need rvm but before doing all this I did need xcode installed
this must be easy for mac experts not for me definitely

Here are simple steps for a mac beginner to get ruby 1.9.3

• Download install xcode from appstore

• Install command line tools from xcode - Go to xcode->preferences->downloads->components->commandline tools 
• Install RVM
        \curl -#L https://get.rvm.io | bash -s stable --autolibs=3 --ruby
• Install ruby using RVM - Install ruby 1.9.3 and use it
  rvm install 1.9.3
  rvm use 1.9.3
   

Errors & Solution

If there are error in RVM installation do this
Type following commands
~ $: source ~/.rvm/scripts/rvm
~ $: type rvm | head -n 1
rvm is a function
~ $: vi ~/.bash_profile add this line into bash_profile 

"source ~/.rvm/scripts/rvm"
Install ruby 1.9.3 and use it