function city(){
    var object1 = document.getElementById('s');
if (object1 != null){
    object1.style.zIndex='-1';
}
document.getElementById('all_city').className='sc';	
}
function uncity(){
var object1 = document.getElementById('s');
if (object1 != null){
    object1.style.zIndex='1';
}
  document.getElementById('all_city').className='hc';  
}