.someclass {  
  position: fixed;  
  top: 0;  
  left: 0;  
  right: 0;  
  bottom: 0;  
  background: rgba(0, 0, 0, 0.8);  
  z-index: 5000;  
  }  

  .loading {  
  position: absolute;  
  top: 50%;  
  left: 50%;  
  margin: -40px 0 0 -150px;  
   
  padding: 10px;  
  background: rgba(0, 0, 0, 0.6);  
  color: #fff;  
  font: normal 11px Verdana;  
  text-shadow: 0 1px 2px #000;  
  text-align: center;  

  border: solid 1px #000;  
  border-radius: 5px;  
  box-shadow: 0 0 10px 2px rgba(255, 255, 255, 0.2);  
  }