Well, apart from the age-old suggestion to look at the javascript section of w3c:
http://www.w3schools.com/js/default.asp[
^], I'd suggest that it can be done with just a handful of elements.
This is a bare-bones page that will present 5 upload controls. I'll leave it to you to
complete the form, especially the 'type' and 'action' attributes - you need to make sure that the form is a multi-part form, you need to post the information to a back-end server page, be it ASPX, PHP, JSP, whatever.
<!DOCTYPE html>
<html>
<head>
<script>
</script>
</head>
<body>
<form>
<input type='file' id='upload1'/><br>
<input type='file' id='upload2'/><br>
<input type='file' id='upload3'/><br>
<input type='file' id='upload4'/><br>
<input type='file' id='upload5'/><br>
</form>
</body>
</html>