1. .btn:link{
    2.     background-image: url(./image/btn.jpg);
    3.     width: 93px;
    4.     height: 18px;
    5.     display: block;
    7. }
    8. .btn:active{
    9.     background-position: -93px 0;
    10. }
    11. .btn:hover{
    12.     background-position: -93px 0;
    13. }