How to simulate user action

[gemini]

Hello,
I've got some slight problem with simulating user action to force login availability check.

I've located JS responsible for that

$('#aLogin')
		.bind('change',loadLogin)
		.bind('keyup',onUpLogin);



var loadLogin = function(){
		if (false == isLoginValid($('#aLogin'))) {
			return;
		}

		var login = cleanVal('aLogin');
		var name = cleanVal('imie');
		var surname = cleanVal('nazwisko');
		WP.$('#loginPropozycja')
			.html('<img src="//i.wp.pl/a/i/profil2/i-p2010/czekaj2.gif" alt="czekaj" style="margin:0 0 7px 322px " />')
			.fadeOut(50)
			.load('czy_login_wolny.html?login=' + login + '&name=' + name + '&surname=' + surname)
			.fadeIn(200);
	}

So it seems that onChange even should be enough.
But calling it doesn't call the action at all. Tried calling also various other event's but no work either.
Any ideas?

Resource url is here (it's polish site) :
https://profil.wp.pl/rejestracja.html?idu=99&serwis=nowa_poczta_wp&url=http://poczta.wp.pl/index.html?flg=1