Trying to prevent submission of the form if the checkbox isn't checked. The alert is working properly but the form still submits after dismissing the alert.

validate-checkbox.js

$(function(){
    $('#NationalPhotoMonth_submitButton').click(function(e) {
        e.preventDefault();
        if(!$('#NationalPhotoMonth_Field_48').is(':checked')){
            alert('You must agree to the term and conditions.');
            return false;
        }        
        if($('#NationalPhotoMonth_Field_48').is(':checked')){            
            return true;
        }
      });
});