window.addEvent('domready', function() {
					
					var pages = ['page1','page2','page3','page4'];
					var menu_pages = ['menu_page1','menu_page2','menu_page3','menu_page4'];
					var selected=0;
					
					var init = function (){
    					$('menu_page1').addClass('current');
    					
    					for (i=1;i<pages.length;i++)
    						$(pages[i]).setStyle('display','none');					
					};
                    
					var hiddenpages = function(s){
    						for (j=0;j<pages.length;j++){
    							if (i!=s)
    							   $(pages[j]).setStyle('display','none');
    						}	
							$(pages[selected]).setStyle('display','block');					
                  	};	
					

					init();
					
					
					$('menu_page1').addEvent('click',function(){
						if (!(this.hasClass('current'))){
    						this.addClass('current');
    						$(menu_pages[selected]).toggleClass('current');
    						selected=0;
    						hiddenpages(selected);
						}
					});
					
					$('menu_page2').addEvent('click',function(){
						if (!(this.hasClass('current'))){			   
    						this.addClass('current');
    						$(menu_pages[selected]).toggleClass('current');
    						selected=1;
    						hiddenpages(selected);
						}							     
					});

					$('menu_page3').addEvent('click',function(){
						if (!(this.hasClass('current'))){
    						this.addClass('current');
    						$(menu_pages[selected]).toggleClass('current');
    						selected=2;
    						hiddenpages(selected);
						}							     
					});
					$('menu_page4').addEvent('click',function(){
						if (!(this.hasClass('current'))){
    						this.addClass('current');
    						$(menu_pages[selected]).toggleClass('current');
    						selected=3;
    						hiddenpages(selected);
						}							     
					});
					
	   		   	});