gistfile1.js

var getData = function(callback){
  showLoadingScreen();
  $.ajax("http://someurl.com", {
    complete: function(data){
      hideLoadingScreen();
      callback(data);
    }
  });		
};

var loadData = function(){
  getData(doSomethingWithTheData);
}

var doSomethingWithTheData = function(data){
 //do something with data
};