function Browser() {

       var ua, s, i;

       this.isIE    = false;  // Internet Explorer
               this.isNS    = false;  // Netscape
               this.version = null;

               ua = navigator.userAgent;

               s = "MSIE";
               if ((i = ua.indexOf(s)) >= 0) {
                   this.isIE = true;
                   this.version = parseFloat(ua.substr(i + s.length));
                   return;
               }

               s = "Netscape6/";
               if ((i = ua.indexOf(s)) >= 0) {
                   this.isNS = true;
                   this.version = parseFloat(ua.substr(i + s.length));
                   return;
               }

               // Treat any other "Gecko" browser as NS 6.1.

               s = "Gecko";
               if ((i = ua.indexOf(s)) >= 0) {
                   this.isNS = true;
                   this.version = 6.1;
                   return;
               }
       }

       var browser = new Browser();

       // Global variable for tracking the currently active button.

       var activeButton = null;

       // Capture mouse clicks on the page so any active button can be
       // deactivated.

       if (browser.isIE)
           document.onclick = pageMousedown;
           if (browser.isNS)
               document.addEventListener("mousedown", pageMousedown, true);

               function pageMousedown(event) {

               var el;

               // If there is no active menu, exit.

               if (!activeButton)
                   return;

                   // Find the element that was clicked on.

                       if (browser.isIE)
                           el = window.event.srcElement;
                       if (browser.isNS)
                       el = (event.target.className ? event.target : event.target.parentNode);

                       // If the active button was clicked on, exit.

                       if (el == activeButton)
                           return;

                           // If the element clicked on was not a menu button or item, close the
                           // active menu.

                           if (el.className != "menuButton"  && el.className != "selcolor" &&
                               el.className != "menuItem" && el.className != "menu" && el.className != "menuButton")
                               resetButton(activeButton);
                           }

                           function buttonClick(button, menuName) {

                             // Blur focus from the link to remove that annoying outline.

                               button.blur();

                                // Associate the named menu to this button if not already done.

  if (!button.menu)
    button.menu = document.getElementById(menuName);

  // Reset the currently active button, if any.

  if (activeButton && activeButton != button)
    resetButton(activeButton);

  // Toggle the button's state.

  if (button.isDepressed)
    resetButton(button);
  else
    depressButton(button);

  return false;
}

function buttonMouseover(button, menuName) {

  // If any other button menu is active, deactivate it and activate this one.
  // Note: if this button has no menu, leave the active menu alone.

  if (activeButton && activeButton != button) {
    resetButton(activeButton);
    if (menuName)
      buttonClick(button, menuName);
  }
}

function depressButton(button) {

  var w, dw, x, y;

  // Change the button's style class to make it look like it's depressed.

  button.className = "menuButtonActive";

  // For IE, set an explicit width on the first menu item. This will
  // cause link hovers to work on all the menu's items even when the
  // cursor is not over the link's text.

  if (browser.isIE && !button.menu.firstChild.style.width) {
    w = button.menu.firstChild.offsetWidth;
    button.menu.firstChild.style.width = w + "px";
    dw = button.menu.firstChild.offsetWidth - w;
      w -= dw;
      button.menu.firstChild.style.width = w + "px";
    }

    // Position the associated drop down menu under the button and
    // show it. Note that the position must be adjusted according to
    // browser, styling and positioning.

    x = getPageOffsetLeft(button);
    y = getPageOffsetTop(button) + button.offsetHeight;
    if (browser.isIE) {
      x += 2;
      y += 2;
    }
    if (browser.isNS && browser.version < 6.1)
      y--;

    // Position and show the menu.

    button.menu.style.left = x + "px";
    button.menu.style.top  = y + "px";
    button.menu.style.visibility = "visible";

    // Set button state and let the world know which button is
    // active.

    button.isDepressed = true;
    activeButton = button;
    }

    function resetButton(button) {

    // Restore the button's style class.

    button.className = "menuButton";

    // Hide the button's menu.

     if (button.menu)
       button.menu.style.visibility = "hidden";

     // Set button state and clear active menu global.

     button.isDepressed = false;
     activeButton = null;
     }

     function getPageOffsetLeft(el) {

     // Return the true x coordinate of an element relative to the page.

       return el.offsetLeft + (el.offsetParent ? getPageOffsetLeft(el.offsetParent) : 0);
     }

     function getPageOffsetTop(el) {

     // Return the true y coordinate of an element relative to the page.

     return el.offsetTop + (el.offsetParent ? getPageOffsetTop(el.offsetParent) : 0);
     }