Task: get GDP data from the new JSON-ified FRED API. Works on command line in node, but not so much in a browser (Chrome 29).

gdp.js

function gdp_get() {

  var fred_api_key = "abcdefghijklmnopqrstuvwxyz0123456789";
	var fred_gdp_url = "http://api.stlouisfed.org/fred/series/observations?series_id=GNPCA&api_key="+fred_api_key+"&file_type=json&callback=?";

	var x = $.getJSON(fred_gdp_url, function(data, status){
		return data;
	});

	var gdp = '';


	if (x.hasOwnProperty("responseText")) {
		gdp = $.parseJSON(x.responseText);
	}

	var gdpObs = gdp.observations;

	gdpObs.forEach(
		function(element, index, array) {
			element['x'] = Math.floor(new Date(element['date']).getTime()/1000);
			element['y'] = Number(element['value']);
			// time to strip out stuff
			delete element['realtime_start'];
			delete element['realtime_end'];
			delete element['date'];
			delete element['value'];
		});

	return gdpObs;

}

I get the following error:

"Uncaught SyntaxError: Unexpected token: http://api.stlouisfed.org/fred/series/observations?series_id=GNPCA&api_key=abcdefghijklmnopqrstuvwxyz&file_type=json&callback=jQuery110109660641909576952_1377221124798&_=1377221124799"

When I actually follow the URL (API key removed), I get the data I expect.

Tried looking at StackOverflow etc, but am finding that I know enough to make me dangerous, but not enough to make sense of the conversations.