вот, набросал
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<style type="text/css">
.input_file
{
position: relative;
width: 200px;
height: 30px;
}
.text
{
position: absolute;
top: 0px;
left: 0px;
width: 130px;
height: 24px;
}
.button
{
position: absolute;
top: 0px;
right: 0px;
width: 60px;
height: 30px;
}
.file
{
height: 30px;
width: 200px;
position: absolute;
top: 0px;
left: 0px;
filter:progid:DXImageTransform.Microsoft.Alpha(opacity=0);
-moz-opacity: 0;
-khtml-opacity: 0;
opacity: 0;
}
</style>
</head>
<body>
<form method="post" action="/login.php">
<div class="input_file">
<input type="text" class="text">
<div class="button">выбрать</div>
<input type="file" class="file">
</div>
</form>
</body>
</html>