[jQuery] function $.ajax return true/false ?

[Gelegrodan]

Hello
I have the following code:

function pnrexists(a){
        $.ajax({
                url: '/inc/chkusr.php?q=p',
                type: 'POST',
                dataType: 'html',
                data: {'pnr': a},
                timeout: 2000,
                success: function(data) {
                        if(data==1){
                                alert('true');
                                return true;
                        }else{
                                alert('false');
                                return false;
                        }
                },
        });
}


the code above is triggered by:


$.validator.addMethod("pnrcheck", function(ph, element) {
        alert('1');
        if(persnr(ph)) {
                alert('2');
                if(pnrexists(ph)) {
                alert('3');
 the code continues..but noting to show...


The problem is: I see:
alert 1
alert 2
alert true
but NOT alert 3?? Why?