The following code shows how to create text input with full width minus button width.
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.8.3.js'></script>
<link rel="stylesheet" type="text/css"
href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/css/bootstrap-combined.min.css">
<script type='text/javascript'
src="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/js/bootstrap.min.js"></script>
</head><!--from w w w .java 2 s . c o m-->
<body style='margin:30px'>
<div class="container">
<div class="row">
<div class="span12 pull-right">
<form class="form-inline">
<button type="submit" class="btn" style="float: right;">Button</button>
<div style="overflow: hidden; padding-right: .3em;">
<input style="height: 1.6em; width: 100%" type="text"
placeholder="full width minus button width" />
</div>
</form>
</div>
</div>
</div>
</body>
</html>