function SDMenu(id) {
       if (!document.getElementById || !document.getElementsByTagName)
              return false;
       this.menu = document.getElementById(id);
       this.submenus = this.menu.getElementsByTagName("div");
       this.remember = true; //czy ma pamiętać jak ostatnio otwarto menu?
       this.speed = 2; // prędkość otwierania/zamykania podmenu (1 - 5 recomended)
       this.markCurrent = true; //zaznaczaj innym kolorem gdzie jesteś w tej chwili
       this.oneSmOnly = true;
}
SDMenu.prototype.init = function() {
       var mainInstance = this;
       for (var i = 0; i < this.submenus.length; i++)
              this.submenus[i].getElementsByTagName("span")[0].onclick = function() {
                     mainInstance.toggleMenu(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++)
                            this.submenus[i].className = (states[i] == 0 ? "collapsed" : "");
              }
       }
       myMenu.collapseAll()
};
SDMenu.prototype.toggleMenu = function(submenu) {
       if (submenu.className == "collapsed")
              this.expandMenu(submenu);
       else
              this.collapseMenu(submenu);
};
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 = "";
                     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 (newHeight > minHeight)
                     submenu.style.height = newHeight + "px";
              else {
                     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.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.memorize = function() {
       if (this.remember) {
              var states = new Array();
              for (var i = 0; i < this.submenus.length; i++)
                     states.push(this.submenus[i].className == "collapsed" ? 0 : 1);
              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=/";
       }
};