help with a simple java app

I need to write a app that will translate a phrase the a user types into Pig Latin,

ex: user types "Hello World", then translates to "ellohay orldway" and displays it in a label or textarea.


Basically taking the first letter of the word, putting at the end of the word, and adding "ay" to it. The user interface code will be seperate from the the actually code that will do the translating. What im not sure of is how to take the user input and manipulate it using the different string commands, then display the result. any help on how to do this, or examples of code where strings are modified this way?