function change_area(area_num) {
	for(i=0; i<=5; i++){
		document.getElementById("area_0" + i).className = "show_off";
		document.getElementById("area_link_0" + i).className = "";
		if(i == area_num){
		document.getElementById("area_0" + i).className = "show_on active";	
		document.getElementById("area_link_0" + i).className = "active";
		}
	}
    
}