.button_wrapper {

height:40px;
width:124px;
overflow:hidden;
}

.button_wrapper a {
height:40px;
width:124px;
overflow:hidden;
display:block;
background:transparent url('BookNow_btn.png') 0px 0px no-repeat;
}

.button_wrapper a:hover {
background:transparent url('BookNow_btn.png') 0px -40px no-repeat;
}

.button_top {position:absolute;
top:-40px;
right:0px;}