nao consigo passar dois parametros via GET

function adicionar(chave,qtd){	var tmp = document.getElementById('rem');	tmp.innerHTML = 'Carregando ...';	ajaxRequest.open("GET", "teste_adiciona.php?chave="+chave+"&qtd="+qtd, true);	ajaxRequest.send(null); ajaxRequest.onreadystatechange = function(){ if(ajaxRequest.readyState == 4){ tmp.innerHTML = ''; tmp.innerHTML = ajaxRequest.responseText; } }} <td> <a href="java script:void(0);" onclick="adicionar('aaa','bbb');">calcular</a></td><? if(isset($_GET['chave'])){ $numero = $_GET['chave']; $qtd = $_GET['qtd']; print $qtd; print $numero; }	?>