function pop_up(id){
	switch(id){
		case 6:
			$('div.pop_up_menu_6').css('visibility', 'visible');
			break;
	}
}

function hidden(id){
	switch(id){
		case 6:
			$('div.pop_up_menu_6').css('visibility', 'hidden');
			break;
	}
}

function preloader(lang) {
     imageObj = new Image();
     images = new Array();
     if(lang == "ch") {
	     images[0]= "./images/menu/btn01a.jpg";
	     images[1]= "./images/menu/btn02a.jpg";
	     images[2]= "./images/menu/btn03a.jpg";
	     images[3]= "./images/menu/btn04a.jpg";
	     images[4]= "./images/menu/btn05a.jpg";
	     images[5]= "./images/menu/btn06a.jpg";
	     images[6]= "./images/menu/btn07a.jpg";
	     images[7]= "./images/menu/btn08a.jpg";
	     images[8]= "./images/menu/btn09a.jpg";
     } else {
	     images[0]= "./images/menu/btn01a_eng.jpg";
	     images[1]= "./images/menu/btn02a_eng.jpg";
	     images[2]= "./images/menu/btn03a_eng.jpg";
	     images[3]= "./images/menu/btn04a_eng.jpg";
	     images[4]= "./images/menu/btn05a_eng.jpg";
	     images[5]= "./images/menu/btn06a_eng.jpg";
	     images[6]= "./images/menu/btn07a_eng.jpg";
	     images[7]= "./images/menu/btn08a_eng.jpg";
	     images[8]= "./images/menu/btn09a_eng.jpg";
     }
     for(var i = 0; i <= images.lenght; i++) {
          imageObj.src = images[i];
     }
}