My first tiny ajax snippet (test)

tjax.first.js

function getAjax(url,params,method){
	var xhr = XMLHttpRequest ? new XMLHttpRequest() : (window.ActiveXObject && new ActiveXObject("Microsoft.XMLHTTP")) || null;
	var _deff = function(){this.fn={};};
	_deff.prototype.text=function(fn){this.fn.text=fn;}
	var get = new _deff();
	xhr.onreadystatechange = function(){
		if (xhr.readyState === 4) {
			if('text' in get.fn&&typeof(get.fn.text)=='function') get.fn.text.call(xhr,xhr.responseText);
		}
	};
	xhr.open(method || 'GET', url || '', true);
	xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
	if(typeof(params)=='string') xhr.setRequestHeader('Content-length', params.length);
	xhr.setRequestHeader("Connection", "close");
	xhr.send(params);
	return get;
}