function cc(num){
    for(var id = 1;id<=7;id++)
    {
    var mainlay="lay"+id;
	var maintt="tt"+id;
    if(id==num){
    document.getElementById(mainlay).style.display="block";
	document.getElementById(maintt).className="bg2";
	}
    else{
	document.getElementById(maintt).className="bg1";
	document.getElementById(mainlay).style.display="none";
	}
  }
}