.change only works once

Using php, mysql and jquery I retrieve countries from a database and fill a select.
When user change the country select, another select (state) should change, filling with states of selected country.

The problem is that the .change event only works when the page load, i.e. within .ready

Why? Thanks!

$(document).ready(function(){
    formAccordion();
    fillCountrySelect();
    ("#paisI").bind('change', fillStatesSelect());
});

function formAccordion(){
    $("#formReg").accordion({header: "h3", autoHeight: false});
}

function fillCountrySelect(){
    $.ajax({
        url: 'locationCountry.php',
        type: "GET",
        success: function(paises){
            $("#paisI").html(paises);
        }
    });
}

function fillStatesSelect(){
    alert("Me llamaste!");
    var pais = $("#paisI").attr('value');
    $.ajax({
        url: 'locationState.php',
        type: "GET",
        data: "submit=&pais="+pais,
        success: function(estados){
            $("#estadoI").html(estados);
        }
    });
}

Code (markup):

I'm sure there's no problem with php files because when the page is ready, first select is filled with countries and the second select is filled with states of Afghanistan (first country).

 

$(document).ready(function(){
    formAccordion();
    fillCountrySelect();
    [B][COLOR=#ff0000][U]$[/U][/COLOR][/B]("#paisI").bind('change', fillStatesSelect());
});

Code (markup):

#paisI's change never got bound to fillStatesSelect