body {background-color:#FED}
.Center {width:40%; margin:10% auto; border: 3px dashed blue; padding:4px}
h2 {text-align:center}
.Conversation {height:500px; overflow:hidden;}
.Conversation table {height:500px; overflow:hidden;}

input {margin:4px;}
input[type="submit"] {border: 5px solid red; background-color:#FDD}
input[type="submit"]:hover {border: 5px solid green; background-color:#DFD}
input[type="submit"]:active {border: 5px solid orange; background-color:#EDC}