.btnWrap {
	background-position:100% 0;
	background-repeat:no-repeat;
	display:inline-block;
	padding-right:3px;
}
.btn {
	background-position:0 0;
	background-repeat:no-repeat;
	border-style:none;
	border-width:0;
	height:22px;
	padding:0 3px 2px 0;
}
.loginBtn {
	background-color: transparent;
	background-image: url(../images/buttons.png);
	color:#000;
}
.loginBtn:hover {
	color:#666;
}

CSS code for input buttons with background images and rounded corners. For cases when it is not possible to use Progressive Enhancement (ie. when you need to have rounded corners in IE6+).
See Customized buttons under HTML for markup.

Customized buttons - rounded corners

ie, button

CSS