function openMenu( item){
        
        var i, j;
        var root;
        var nodes;
        
        root = document.getElementById('nav');
        
        nodes = root.getElementsByTagName('a');

        j = 0;
        
        for( i = 0; i < nodes.length; i ++){
            
            if( nodes[i].className.indexOf('bimuyu') == 0){
            
                j ++;
                        
                if( item == j) nodes[i].className = 'bimuyu active';
            
                else nodes[i].className = 'bimuyu';
                
            }            
            
        }
        
        activeMenu( item);
        
    }

    function activeMenu( item){
        
        var i;
        var root;
        var nodes;
        var name;
        
        root = document.getElementById('nav');
        
        nodes = root.getElementsByTagName('ul');
        
        for( i = 0; i < nodes.length; i ++){
            
            if( nodes[i].className.indexOf('submenu') == 0){
                        
                name = 'submenu sub' + item;
                
                if( nodes[i].className == name) nodes[i].style.display = 'block';
                
                else nodes[i].style.display = 'none';
                
            }            
            
        }        
        
    }
    
    function initMenu(){

        var i, j;
        var root;
        var nodes;
        var item;
        
        root = document.getElementById('nav');
        
        nodes = root.getElementsByTagName('a');

        j = 0;
        
        for( i = 0; i < nodes.length; i ++){
            
            if( nodes[i].className.indexOf('bimuyu') == 0){

                j ++;
                        
                if( nodes[i].className == 'bimuyu active'){
                
                    item = j;
                
                    break;
                
                }
                
            }            
            
        }
        
        activeMenu( item);        
        
    }