function showhideFields() {
        var selValue = $("#id_q_organization option:selected").attr("class"); 
        switch(selValue)
        {
            case 'reseller':
                $("#reseller-field").show()
                break;
            default:
                $("#reseller-field").hide()
                $("#reseller-field option[value=0]").attr('selected', 'selected')
                break;
        }
    }

$(document).ready(function(){ 
    showhideFields();
    $('#id_q_organization').change(showhideFields);
});