var xmlhttp;

function loadXMLDoc(url) {
    xmlhttp = null;
    // code for Mozilla, etc.
    if (window.XMLHttpRequest) {
        xmlhttp = new XMLHttpRequest();
    }
    // code for IE
    else if (window.ActiveXObject) {
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    if (xmlhttp != null) {
        xmlhttp.open("GET", url, true);
        xmlhttp.send(null);
    }
    else {
        // browser does not support XMLHTTP
    }
}

$(document).ready(function () {

    $('.hoverbutton').mouseenter(function () {
        $(this).attr('src', $(this).attr('src').replace('.png', '_active.png'));
    });

    $('.hoverbutton').mouseleave(function () {
        $(this).attr('src', $(this).attr('src').replace('_active.png', '.png'));
    });

});