My spry menu has disappeared. Help!

Question

I had my spry menu all set except for it wasn't quite long enough. In the process of getting the width correct, it went transparent. I can see the menu items properties and in the code and the blue box is there. I just can't see the menu itself in Dreamweaver or online. I can't figure out what I changed that made it do this.
ul.MenuBarHorizontal
    list-style-type: none;
    cursor: default;
width: 890
`;
    text-align: center;
    float: left;
    z-index: 1000;
    width: 878px;
    clear: none;
    border-top-style: none;
    border-right-style: none;
    border-bottom-style: none;
    border-left-style: none;
    padding: 0px;
    clip: rect(auto,0px,auto,0px);
    margin: 0px;
    position: relative;
    height: inherit;
    left: 147px;
    top: 0px;
    right: 0px;
    bottom: 0px;
/* Set the active Menu Bar with this class, currently setting z-index to accomodate IE rendering bug: http://therealcrisp.xs4all.nl/meuk/IE-zindexbug.html */
ul.MenuBarActive
    z-index: 1000;
    text-align: left;
    float: none;
    width: auto;
    clear: right;
    height: auto;
/* Menu item containers, position children relative to this container and are a fixed width */
ul.MenuBarHorizontal li
    margin: 0px;
    padding: 0;
    list-style-type: none;
    font-size: 105%;
    text-align: center;
    cursor: pointer;
    font-family: "Trebuchet MS", Arial, Helvetica, sans-serif, Biondi;
    z-index: auto;
    font-weight: normal;
    white-space: normal;
    display: block;
    width: auto;
    height: auto;
    float: left;
    position: absolute;
    left: 315px;
    top: -310px;
/* Submenus should appear below their parent (top: 0) with a higher z-index, but they are initially off the left side of the screen (-1000em) */
ul.MenuBarHorizontal ul
    margin: 0;
    padding: 0;
    list-style-type: none;
    z-index: 1020;
    cursor: default;
    width: auto;
    left: -1000em;
    text-align: left;
    float: none;
    clear: right;
    position: relative;
    height: auto;
/* Submenu that is showing with class designation MenuBarSubmenuVisible, we set left to auto so it comes onto the screen below its parent menu item */
ul.MenuBarHorizontal ul.MenuBarSubmenuVisible
    text-align: left;
    left: auto;
    width: auto;
    clear: right;
    float: none;
    position: relative;
/* Menu item containers are same fixed width as parent */
ul.MenuBarHorizontal ul li
    width: auto;
    float: none
!important;
    display: block;
    white-space: nowrap;
    text-align: left;
    clear: right;
/* Submenus should appear slightly overlapping to the right (95%) and up (-5%) */
ul.MenuBarHorizontal ul ul
    text-align: left;
    width: auto;
    margin-top: -5%;
    margin-right: 0;
    margin-bottom: 0;
    margin-left: 95%;
    clear: right;
    float: none;
    position: relative;
/* Submenu that is showing with class designation MenuBarSubmenuVisible, we set left to 0 so it comes onto the screen */
ul.MenuBarHorizontal ul.MenuBarSubmenuVisible ul.MenuBarSubmenuVisible
    left: auto;
    top: auto;
    text-align: left;
    right: auto;
    bottom: auto;
    height: auto;
    width: auto;
    float: none;
    clear: right;
DESIGN INFORMATION: describes color scheme, borders, fonts
/* Submenu containers have borders on all sides */
ul.MenuBarHorizontal ul
    text-align: center;
    width: auto;
    border-top-width: 0px;
    border-right-width: 0px;
    border-bottom-width: 0px;
    border-left-width: 0px;
    float: none;
    padding: 0em;
    clear: right;
    position: relative;
/* Menu items are a light gray block with padding and no text decoration */
ul.MenuBarHorizontal a
    display: block;
    cursor: default;
    background-color: #102842;
    text-decoration: none;
    text-align: left;
    border: thin inset #FFF;
    color: #FFF;
    letter-spacing: normal;
    word-spacing: normal;
    width: auto;
    list-style-type: none;
    margin: auto;
    float: none;
    padding-top: 0.25em;
    padding-right: 0.75em;
    padding-bottom: 0.75em;
    padding-left: 0.25em;
    font-family: "Trebuchet MS", Arial, Helvetica, sans-serif, Biondi;
    font-size: 100%;
    clear: right;
    position: relative;
/* Menu items that have mouse over or focus have a blue background and white text */
ul.MenuBarHorizontal a:hover, ul.MenuBarHorizontal a:focus
    background-color: #FFF;
    color: #102842;
    text-align: center;
    padding: 0px;
    width: auto;
    float: none;
/* Menu items that are open with submenus are set to MenuBarItemHover with a blue background and white text */
ul.MenuBarHorizontal a.MenuBarItemHover, ul.MenuBarHorizontal a.MenuBarItemSubmenuHover, ul.MenuBarHorizontal a.MenuBarSubmenuVisible
    background-color: #FFF;
    color: #0D8C17;
    padding: 0px;
    text-align: left;
    margin: auto;
    width: auto;
SUBMENU INDICATION: styles if there is a submenu under a given menu item
/* Menu items that have a submenu have the class designation MenuBarItemSubmenu and are set to use a background image positioned on the far left (95%) and centered vertically (50%) */
ul.MenuBarHorizontal a.MenuBarItemSubmenu
    text-align: left;
    margin: auto;
    width: auto;
    padding: 0.5em;
    float: none;
    clear: right;
    position: relative;
/* Menu items that have a submenu have the class designation MenuBarItemSubmenu and are set to use a background image positioned on the far left (95%) and centered vertically (50%) */
ul.MenuBarHorizontal ul a.MenuBarItemSubmenu
    background-image: url(SpryMenuBarRightHover.gif);
    background-repeat: no-repeat;
    background-position: 95% 50%;
    background-color: #102842;
    text-align: left;
    width: auto;
/* Menu items that are open with submenus have the class designation MenuBarItemSubmenuHover and are set to use a "hover" background image positioned on the far left (95%) and centered vertically (50%) */
ul.MenuBarHorizontal a.MenuBarItemSubmenuHover
    background-image: none;
    text-align: left;
    position: relative;
    width: auto;
/* Menu items that are open with submenus have the class designation MenuBarItemSubmenuHover and are set to use a "hover" background image positioned on the far left (95%) and centered vertically (50%) */
ul.MenuBarHorizontal ul a.MenuBarItemSubmenuHover
    background-image: url(SpryMenuBarRight.gif);
    background-repeat: no-repeat;
    background-position: 95% 50%;
    background-color: #FFF;
    text-align: left;
    position: relative;
BROWSER HACKS: the hacks below should not be changed unless you are an expert
/* HACK FOR IE: to make sure the sub menus show above form controls, we underlay each submenu with an iframe */
ul.MenuBarHorizontal iframe
    z-index: 1010;
filter:alpha(opacity:0.1);
    text-align: left;
    position: relative;
/* HACK FOR IE: to stabilize appearance of menu items; the slash in float is to keep IE 5.0 from parsing */
@media screen, projection
    ul.MenuBarHorizontal li.MenuBarItemIE
    display: block;
    f\loat: left;
    background: #FFF;
    text-align: left;
    position: relative;
    width: auto;
<ul class="MenuBarHorizontal" id="MenuBar1">
<li><a href="#">HOME</a></li>
    <li><a href="#" class="MenuBarItemSubmenu">ABOUT US</a>
      <ul>
        <li><a href="#">Become a Member</a></li>
        <li><a href="#">Photo Gallery</a></li>
        <li><a href="#">Contact Us</a></li>
      </ul>
    </li>
    <li><a href="#" class="MenuBarItemSubmenu">NEWS</a>
      <ul>
        <li><a href="#">Events</a></li>
        <li><a href="#">Photo Gallery</a></li>
        <li><a href="#">Job Listings</a></li>
        <li><a href="#">Hot Deals</a></li>
      </ul>
    </li>
    <li><a href="#" class="MenuBarItemSubmenu">COMMUNITY</a>
      <ul>
        <li><a href="#">Scott Air Force Base</a></li>
        <li><a href="#">City of O'Fallon</a></li>
        <li><a href="#">O'Fallon Welcome Guide</a></li>
        <li><a href="#">O'Fallon-Shiloh Area Restaurant Guide</a></li>
        <li><a href="#" class="MenuBarItemSubmenu">Shiloh</a>
          <ul>
            <li><a href="#">Village of Shiloh</a></li>
            <li><a href="#">Village Services Guide</a></li>
          </ul>
        </li>
<li><a href="#">Events &amp; Reception Planning Guide</a></li>
        <li><a href="#">Relocation Packet Info</a></li>
        <li><a href="#">The Tourism Bureau Illinois South</a></li>
      </ul>
    </li>
    <li><a href="#" class="MenuBarItemSubmenu">COMMITTEES</a>
      <ul>
        <li><a href="#">Board of Directors</a></li>
        <li><a href="#">Ambassadors</a></li>
        <li><a href="#">Star Investors</a></li>
        <li><a href="#">Member Directory</a></li>
      </ul>
    </li>
    <li><a href="#" class="MenuBarItemSubmenu">CONTACT US</a>
      <ul>
        <li><a href="#">Member Login</a></li>
        <li><a href="#">Member Directory</a></li>
        <li><a href="#">Relocation Packet Info</a></li>
        <li><a href="#">Community Business Info</a></li>
      </ul>
    </li>
    <li><a href="#" class="MenuBarItemSubmenu">EVENTS</a>
      <ul>
        <li><a href="#">News</a></li>
        <li><a href="#">Calendar</a></li>
        <li><a href="#">Photo Gallery</a></li>
        <li><a href="#">Hot Deals</a></li>
      </ul>
    </li>
    <li><a href="#" class="MenuBarItemSubmenu">JOIN</a>
      <ul>
        <li><a href="#">Member Directory</a></li>
        <li><a href="#">Become a Member</a></li>
        <li><a href="#">Hot Deals</a></li>
        <li><a href="#">Member Login</a></li>
        <li><a href="#">Community Business Info</a>
<br />
</li>
      </ul>
    </li>
  </ul>

Answer 1

I added the following to the document (after the link to SpryMenuBarHorizontal.css)
<style>
ul.MenuBarHorizontal li {
    top: auto;
    position: relative;
</style>
and managed to see the menubar.
However, while perusing the stylesheet, I noticed that it had been mistreated beyond recognition. In view of this, I would recommend starting with an untouched stylesheet and changing only the colours and font sizes of existing style rules. Do not add new rules, do not delete existing rules.
See how you go and report back here in case of trouble.