Ajax Call Returns 403 From Asp

Question

There is a classic Asp website and we have developed a handler that would be a bridge between the website and a web service. But all I get is 403(Forbidden) error. Here is my Ajax :

$.ajax({
    url: 'test.ashx',
    type: 'POST',
    data: {
        'email': '[email protected]',
        'name': 'test',
        'surname': 'test',
        'gsm': 'test',
        'GSM_PERMIT': 'L',
        'CALL_PERMIT': 'L',
        'EMAIL_PERMIT': 'L',
        'selectedaccounts': 'testa, testb'
    },
    dataType: 'json',
    success: function(data) {}
});

What could be the problem? Any help is appriciated, thanks in advance