$(document).ready(
    function() 
    {
        $('.newsLetterImgBtnHover').hover(
            function() {    $(this).attr('src', '/images/common_images/NewsletterButtons/signup_button_hover.jpg');     },
            function() {    $(this).attr('src', '/images/common_images/NewsletterButtons/signup_button_static.jpg');    }
        );        
    }
);