xhr functions for GET and POST (currently meant for Chrome only)

xhrs.js

/*global window */
window['DEBUG'] = window['DEBUG'] || 1;

function xhr_GET(method, url, callback, opt_args){
	/* http://developer.chrome.com/extensions/xhr.html */
	
	if (window['DEBUG']){ window.console.log('making xhr GET request for url: '+url);}
	var timeout= 2000;
	var xhr = new window.XMLHttpRequest();
	xhr.ontimeout = function () {
		console.error("The request for " + url + " timed out.");
	};
	xhr.onerror = function(){
		console.error("error: "+xhr.statusText);
	}
	xhr.onload = function() {
		if (xhr.status === 200) {
			window.console.log("response: "+xhr.response);
			var response = '';
			try{
				response = JSON.parse(xhr.response);
			} catch (e){
				response = 'error';
				window.console.log('JSON parsing error; could not parse response: ', e);
			}
			callback(response);
		}  else {
			console.error(xhr.statusText);
		}
		
	};
		
	xhr.timeout = timeout;

	if (typeof opt_args != 'undefined'){
		url = url + '?' + opt_args;
	}
	xhr.open('GET', url, true);
	xhr.send();
	
}

function xhr_POST(url, callback, opt_args){
	/* http://developer.chrome.com/extensions/xhr.html */
	
	if (window['DEBUG']){ window.console.log('making xhr POST request for url: '+url);}
	var timeout= 2000;
	var xhr = new window.XMLHttpRequest();
	xhr.ontimeout = function () {
		console.error("The request for " + url + " timed out.");
	};
	xhr.onerror = function(){
		console.error("error: "+xhr.statusText);
	}
	xhr.onload = function() {
		if (xhr.status === 200) {
			window.console.log("response: "+xhr.response);
			var response = '';
			try{
				response = JSON.parse(xhr.response);
			} catch (e){
				response = 'error';
				window.console.log('JSON parsing error; could not parse response: ', e);
			}
			callback(response);
		}  else {
			console.error(xhr.statusText);
		}
		
	};
		
	xhr.timeout = timeout;
	
	xhr.open('POST', url, true);
	xhr.setRequestHeader("Content-type","application/x-www-form-urlencoded");
	if (typeof opt_args != 'undefined'){
		xhr.send(opt_args);
	}

}