$(document).ready(function() {
    var options = {
        success: showResponse
    }
        , update_message = $('#stay_updated_message')
        , email_field = $('#email_field')
        , submit_button = $('#submit_email_form')
    
    $("#email_signup_form").ajaxForm(options);
    
    function showResponse(responseText, statusText, xhr, $form){
        update_message.text("Thanks! We'll be in touch.");
        email_field.val('');
    }
    
    email_field.bind('keyup', function(){
        if(isEmailValid($(this).val())){
            submit_button.attr('src', '/static/images/mailsubmit_active.png');
        } else {
            submit_button.attr('src', '/static/images/mailsubmit_inactive.png');
        }
    });
    
    function isEmailValid(strEmail) {
        validRegExp = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
        if (strEmail.search(validRegExp) == -1) {
            return false;
        }
        return true;
    }
    
    
});