I'm creating some domain availability checker for multiple domains in PHP in combination with Ajax.
Everything works, except, Ajax.Updater from Prototype waits until one task is finished before it starts the next task. So there are no simultaneous lookups, it's like Prototype puts all the requests in some queue.

Is there a way to force simultaneous requests?

function doLookup(){
 for(i = 0; i < ids.length; i++){
  checkADomain(ids[i], exts[i], domains[i]);
window.onload = function(){ doLookup(); }
function checkADomain(id, ext, domain){
 /* same problem with Ajax.Updater */
 new Ajax.Request('index.php?do=checkdomain',   {
 method: 'post',
 parameters: {domain: domain, ext: ext, id: id},
 onComplete: function(transport){