form {
    position:absolute;
    left:50%;
    margin-left:-300px;
    margin-top:50px;
    padding:1em;
    width:600px;
    line-height: 1.8em;
    /* height:80px; */
    border:1px solid gray;
    text-align:center;
}

form div {
    text-align:center;
    height:50%;
}

form p{
    font-size:0.9em;
    margin-bottom:1em;
}

div input{
    vertical-align:middle;
}