$(document).ready(function() {
    $('#affiliate-form').submit(function() {
        var has_error = false;
        if( $('#fullname').val() == ''){
            $('#fullname_required').css('display','block');
            has_error = true;
        } else {
            $('#fullname_required').css('display','none');
        }
            
        if( $('#email').val() == ''){
            $('#email_required').css('display','block');
            has_error = true;
        } else {
            $('#email_required').css('display','none');
        
            if( !isValidEmailAddress($('#email').val()) ){
                $('#email_invalid').css('display','block');
                has_error = true;
            } else {
                $('#email_invalid').css('display','none');   
            }
        }

        return !has_error;
    });
});