// Determine browser and version.
		
		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.onmousedown = 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 != "menuItem" &&
		      el.className != "menuItemSep" && el.className != "menu")
		    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);
		}