title: How to Dynamically populate values in a UIPicker
body: <p>Ok, maybe I'm missing something really simple and I apologize if that's the case, however, I've googled every permutation of the title and have not found! 
  Here's my question, my requirement is when i select a country name in a uipicker component, the cities of that country should be loaded in the second UIPicker component. 
  So what i want to do ryt now is, i have 2 picker views side by side and when the user selects a row in country picker i want to re-initiate the second picker with appropriate data.</p>
  
  <p>Any help is appreciated !!</p>