// validate version of browser
var valid_browser;
valid_browser = (navigator.appName == "Netscape" && parseInt(navigator.appVersion) >= 3.0) || (navigator.appName == "Microsoft Internet Explorer" && parseInt(navigator.appVersion) >= 4.0);

var image_array;
image_array = new Array();

function roll_image(image_object, src_mouseover_image, src_normal_image, status) {

    this.image_object = image_object;
    this.src_mouseover_image = src_mouseover_image;
    this.src_normal_image = src_normal_image;
    this.status = status;
}

// this will pre-load the image for the mouse over
function load_image(object_name, image_name, src_mouseover_image, status) {

    // don't worry if not a valid browser
    if (valid_browser) {

        // pump into array
        image_array[object_name] = new roll_image(document.images[image_name], src_mouseover_image, document.images[image_name].src, status);

        // pre-load image
        image_array[object_name].image_object_over = new Image();
        image_array[object_name].image_object_over.src = src_mouseover_image;

        // pre-load normal for IE
        image_array[object_name].image_object_normal = new Image();
        image_array[object_name].image_object_normal.src = document.images[image_name].src;
    }

    return true;
}

// this is for mouse over
function roll_over(object_name) {

    if (valid_browser) {

        // swap the image
        image_array[object_name].image_object.src = image_array[object_name].src_mouseover_image;

        // and set the status
        if (image_array[object_name].status != null && image_array[object_name].status != '' && image_array[object_name].status != 'undefined') {
            window.status = image_array[object_name].status;
        }
    }

    return true;
}

// this is for mouse out
function roll_out(image_name) {

    if (valid_browser) {

        // swap the image back
        image_array[image_name].image_object.src = image_array[image_name].src_normal_image;

        // and blank out the status
        window.status = '';
    }

    return true;
}