which_image_loaded = 0;
NUMBER_OF_IMAGES = 25;
ImageNames = new Array();
ImageNames.length = NUMBER_OF_IMAGES - 1;
descList = new Array();

j = 1;
for(i = 0; i < 25; i++) {
    ImageNames[i] = ("images/slideshow/property" + j + ".gif");
    j += 1;
}

function slide(direction) {
    which_image_loaded += direction;
    if (which_image_loaded < 0)
        which_image_loaded = NUMBER_OF_IMAGES - 1;

    if (which_image_loaded == NUMBER_OF_IMAGES)
        which_image_loaded = 0;

    if (document.images)
        document.getElementById("bigImage").src = ImageNames[which_image_loaded];
}