var intCancelCollapse   = false;

function SDMenu(id) {
	if (!document.getElementById || !document.getElementsByTagName)
   {
		return false;
   }
	this.menu = document.getElementById(id);
	this.submenus = this.menu.getElementsByTagName("div");
	this.remember = true;
	this.speed = 3;
	this.markCurrent = true;
	this.oneSmOnly = false;
}
SDMenu.prototype.init = function() {
	var mainInstance = this;
	for (var i = 0; i < this.submenus.length; i++)
   {
      // Setup the event handlers for the top level meny items.
		this.submenus[i].getElementsByTagName("span")[0].onclick = function() {
			mainInstance.toggleMenu(this.parentNode);
		};

		this.submenus[i].getElementsByTagName("span")[0].onmouseover = function() {
			mainInstance.mouseOverMenu(this.parentNode);
		};

		this.submenus[i].getElementsByTagName("span")[0].onmouseout = function() {
			mainInstance.mouseOutMenu(this.parentNode);
		};

      // Setup the mouse over and out handlers for the first menu item in each menu.
		this.submenus[i].getElementsByTagName("a")[0].onmouseover = function() {
			mainInstance.mouseOverMenuItem(this.parentNode);
		};

		this.submenus[i].getElementsByTagName("a")[0].onmouseout = function() {
			mainInstance.mouseOutMenuItem(this.parentNode);
		};
   }
	if (this.markCurrent)
   {
		var links = this.menu.getElementsByTagName("a");
		for (var i = 0; i < links.length; i++)
      {
			if (links[i].href == document.location.href)
         {
				links[i].className = "current";
				break;
			}
      }
	}
	if (this.remember)
   {
		var regex = new RegExp("sdmenu_" + encodeURIComponent(this.menu.id) + "=([01]+)");
		var match = regex.exec(document.cookie);
		if (match)
      {
			var states = match[1].split("");
			for (var i = 0; i < states.length; i++)
         {
            if (states[i] == 0)
            {
               this.submenus[i].className = "collapsed";
            }
            else
            {
               this.submenus[i].className = "expanded";
            }
         }
		}
	}
};
SDMenu.prototype.toggleMenu = function(submenu) {
	var mainInstance = this;
	
   if (submenu.className == "collapsed")
   {
		this.expandMenu(submenu);
   }
   else if (submenu.className == "expanded")
   {
		this.collapseMenu(submenu);
   }
   else if (submenu.className == "temp")
   {
      submenu.className = "expanded";
      mainInstance.memorize();
   }
};

// Mouse Over for a parent menu. 
SDMenu.prototype.mouseOverMenu = function(submenu) {
	if (submenu.className == "collapsed")
   {
		this.expandMenuTemp(submenu);
   }
};

// Mouse Out for a parent menu.
SDMenu.prototype.mouseOutMenu = function(submenu) {
   if (submenu.className == "temp")
   {
      this.collapseMenu(submenu);
   }
};

// Mouse Over handler for menu items cancels any collapse of it's parent menu.
SDMenu.prototype.mouseOverMenuItem = function(menuitem) {
   intCancelCollapse = true;
};

// Mouse Out handler for menu items allows collapse of it's parent menu.
SDMenu.prototype.mouseOutMenuItem = function(menuitem) {
   intCancelCollapse = false;
};

SDMenu.prototype.expandMenu = function(submenu) {
	var fullHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
	var links = submenu.getElementsByTagName("a");
	for (var i = 0; i < links.length; i++)
   {
		fullHeight += links[i].offsetHeight;
   }
	
   var moveBy = Math.round(this.speed * links.length);
	
	var mainInstance = this;
	var intId = setInterval(function() {
		var curHeight = submenu.offsetHeight;
		var newHeight = curHeight + moveBy;
		if (newHeight < fullHeight)
      {
			submenu.style.height = newHeight + "px";
      }
		else
      {
			clearInterval(intId);
			submenu.style.height = "";
			submenu.className = "expanded";
			mainInstance.memorize();
		}
	}, 30);
	this.collapseOthers(submenu);
};
SDMenu.prototype.expandMenuTemp = function(submenu) {
	var fullHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
	var links = submenu.getElementsByTagName("a");
	for (var i = 0; i < links.length; i++)
   {
		fullHeight += links[i].offsetHeight;
   }
	
   var moveBy = Math.round(this.speed * links.length);
	
	var mainInstance = this;
	var intId = setInterval(function() {
		var curHeight = submenu.offsetHeight;
		var newHeight = curHeight + moveBy;
		if (newHeight < fullHeight)
      {
			submenu.style.height = newHeight + "px";
      }
		else
      {
			clearInterval(intId);
			submenu.style.height = "";
			submenu.className = "temp";
			mainInstance.memorize();
		}
	}, 30);
	this.collapseOthers(submenu);
};
SDMenu.prototype.collapseMenu = function(submenu) {
	var minHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
	var moveBy = Math.round(this.speed * submenu.getElementsByTagName("a").length);
	var mainInstance = this;
	var intId = setInterval(function() {
		var curHeight = submenu.offsetHeight;
		var newHeight = curHeight - moveBy;
		if (intCancelCollapse)
      {
         intCancelCollapse    = false;
			clearInterval(intId);
		}
		else if (newHeight > minHeight)
      {
			submenu.style.height = newHeight + "px";
      }
		else if (newHeight <= minHeight)
      {
			clearInterval(intId);
			submenu.style.height = "";
			submenu.className = "collapsed";
			mainInstance.memorize();
		}
	}, 30);
};
SDMenu.prototype.collapseOthers = function(submenu) {
	if (this.oneSmOnly)
   {
		for (var i = 0; i < this.submenus.length; i++)
      {
			if (this.submenus[i] != submenu && this.submenus[i].className != "collapsed")
         {
				this.collapseMenu(this.submenus[i]);
         }
      }
	}
};
SDMenu.prototype.expandAll = function() {
	var oldOneSmOnly = this.oneSmOnly;
	this.oneSmOnly = false;
	for (var i = 0; i < this.submenus.length; i++)
   {
		if ((this.submenus[i].className == "collapsed") ||
          (this.submenus[i].className == "temp"))
      {
			this.expandMenu(this.submenus[i]);
      }
   }
	this.oneSmOnly = oldOneSmOnly;
};
SDMenu.prototype.collapseAll = function() {
	for (var i = 0; i < this.submenus.length; i++)
   {
		if (this.submenus[i].className != "collapsed")
      {
			this.collapseMenu(this.submenus[i]);
      }
   }
};
SDMenu.prototype.collapseAllTemp = function() {
	for (var i = 0; i < this.submenus.length; i++)
   {
		if (this.submenus[i].className == "temp")
      {
			this.collapseMenu(this.submenus[i]);
      }
   }
};
SDMenu.prototype.memorize = function() {
	if (this.remember)
   {
		var states = new Array();
		for (var i = 0; i < this.submenus.length; i++)
      {
         var state;
         if (this.submenus[i].className == "collapsed" )
         {
            state = 0;
         }
         else
         {
            state = 1;
         }

			states.push(state);
      }

		var d = new Date();
		d.setTime(d.getTime() + (30 * 24 * 60 * 60 * 1000));
		document.cookie = "sdmenu_" + encodeURIComponent(this.menu.id) + "=" + states.join("") + "; expires=" + d.toGMTString() + "; path=/";
	}
};