gistfile1.js

function gimmeDatJSON(callback) {
  $.getJSON(geourl, function(response) {
    callback(response);
  });
}

function processResponse(response) {
  var lat = response.results[0].geometry.location.lat;
  var lng = response.results[0].geometry.location.lng;
    
  // do something with lat & lng
}

$('#submit').bind('click', function() {
  
  gimmeDatJSON(function(response) {
    processResponse(response);
  });
  
});