Simple HTTP request wrapper for XMLHttpRequest

simplehttprequest.js

function http(url, method, data){
	return new Promise(function(resolve, reject) {
		var xhr;
		if(method == undefined) method = data ? "POST" : "GET";
		try {
			xhr = new XMLHttpRequest();
		} catch (e) {
			xhr = new ActiveXObject("Msxml2.XMLHTTP");
		}

		xhr.onreadystatechange = function () {
			if (xhr.readyState == 4) {
				if (xhr.status == 200) {
					resolve(xhr.responseText);
				} else {
					reject(xhr);
				}
			}
		}
		xhr.error = function(e) {
			reject(xhr);
		}
		xhr.open(method, url, true); 
		xhr.send(data);
	});
}