.oc{
display: block;
border: none;
background: transparent 0 0 no-repeat;
width: 25px;
height: 25px;
font-size:0px;
padding-top: 45px;
height: expression(this.scrollHeight > 25? "25px" : "auto");
max-height:25px;
cursor: pointer;
}

.oc::-moz-focus-inner {
border: none;
}