Just thought I'd share some CSS I found for changing the format of Form buttons - Submit, Preview etc.
.button {
	background-color: #999966;
	color: #FFFFFF;
	cursor: hand;
	font-size: 10px;
	font-weight: bold;
	height: 18px;
	text-align: center;
	text-transform: uppercase;
	vertical-align: middle;
	width: 88px;
}	
Any time you want to use it just put class=""button"" in your code that generates a form button. eg:
<input name=""Submit"" type=""submit"" value=""Submit"" class=""button"">