<!-- form search bar #1 -->

<form method="get" action="http://designmoo.com/" name="search">
<input id="s" type="text" value="" name="s">
<input id="submit" class="submit" type="submit" value="Search" name="submit">
</form>

<!-- form search bar #2 -->

<div>
	<input type="text" name="search" placeholder="search">
	<input type="submit" name="search" value="go" class="search">
</div>

<!--css for form search bar # 2-->

nav ul li div input[type=text]{
	-webkit-border-radius: 20px;
	-moz-border-radius: 20px;
	background: #4b9241;
	border-left: none;
	border-right: none;
	border-bottom: 1px solid #5ead52;
	border-top: 1px solid #346d2c;
	color: #fff;
	text-shadow: 0 1px 0 #387031;
	padding: 5px 0 5px 20px;
	width: 200px;
}

Form - Search bar

HTML