CSS Coded

<style>
.search { 
width: 260px; 
padding: 0 10px; 
height: 42px; 
background: #8CDAF8; 
}
.search .searchform { 
margin:7px 0; 
display: inline; 
height:29px; 
}
.search .searchbutton {
	margin: 8px 0 0 0;
	background: #777;
	width:30px;
	height:26px;
	font: normal 14px/14px 'Trebuchet MS', sans-serif;
	color:#FFF;
	border: 0;
}
.search .searchbx {
	font: italic normal 15px/15px Georgia, serif;
	color: #555;
	border: none !important;
	height: 20px;
	width: 226px;
	padding: 0 0 3px;
	background-color: transparent !important;
}
</style>

Markup HTML

<div class="search">
<form class="searchform" action="http://undercover-blogger.blogspot.com/search" method="get" target="top">
<input name="q" type="text" class="searchbx" size="" placeholder="Type here to search..." />
<input type="submit" class="searchbutton" value="OK" />
</form>
</div>

Very simple form search box
Here for play coded http://undercover-blogger.blogspot.com/p/html-editor.html

Simple Form Search Box

html

HTML