The following code shows how to create button with rounded corners with form-search.
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.8.3.js'></script>
<script type='text/javascript'
src="http://appliedinter.net/Workstream/common_files/js/plugins.js"></script>
<script type='text/javascript'
src="http://appliedinter.net/Workstream/common_files/js/script.js"></script>
<script type='text/javascript'
src="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.2/js/bootstrap.min.js"></script>
<link rel="stylesheet" type="text/css"
href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.2/css/bootstrap-combined.min.css">
</head><!--from w ww. j a va 2s . c om-->
<body>
<div class="alert alert-error">
<form class="form-search">
<div class="input-append">
<input type="text" class="span2 search-query">
<button type="submit" class="btn">Quick</button>
<a href="somewhere.html" class="btn">Full</a>
</div>
</form>
</div>
</body>
</html>