var ie = /MSIE/.test(navigator.userAgent);
var moz = !ie && navigator.product == "Gecko";

if (moz) {
     HTMLElement.prototype.__defineGetter__("children", function() {
           var arr = new Array(), i = 0, l = this.childNodes.length;
           for ( i = 0; i < l; i++ ) {
               if ( this.childNodes[ i ].nodeType == 1 ) {
                    arr.push( this.childNodes[ i ] );
               }
           }
      return arr;
      });

      HTMLElement.prototype.__defineGetter__("firstChild", function() {
            var node = this.childNodes[ 0 ];
            while (node.nodeType != 1) node = node.nextSibling;
                 return node;
            });

     HTMLElement.prototype.__defineGetter__("lastChild", function() {
     var node = this.childNodes[ this.childNodes.length - 1 ];
     while (node.nodeType != 1) node = node.previousSibling;
           return node;
      });
}

function openMenuList(el)
{
   if(Element.hasClassName(el, 'clicked') && !Element.hasClassName(el, 'dont')){
     Element.removeClassName(el, 'clicked');
   }else{
     Element.addClassName(el, 'clicked');
     var childrens= document.getElementById('nav').children;
     
     for(var i =0; i<childrens.length;i++){
    	var child = childrens[i];  
       if(Element.hasClassName(child, 'clicked') && child!=el && !Element.hasClassName(child, 'dont')){
         Element.removeClassName(child, 'clicked');
       };
     }

   }
}
function dontChange(el){
  
  if(!Element.hasClassName(el.parentNode.parentNode, 'clicked')){
    Element.addClassName(el.parentNode.parentNode, 'clicked');
  }else{
    Element.addClassName(el.parentNode.parentNode, 'dont');
  }
}