Modifique un codigo que tenia que encontre por ahi para hacer upload multiple.. y lo adapte.. espero te sirva al menos como idea..
Código HTML:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script language="javascript" type="text/javascript">
var upload_number=1;
function addFileInput() {
var i=0;
var d = document.createElement("div");
var file0 = document.createElement("select");
file0.setAttribute("name", "select[]");
file0.options[i] = new Option('fas','saf');
i++;
file0.options[i] = new Option('fdd','fsa');
d.appendChild(file0);
var file = document.createElement("input");
file.setAttribute("type", "text");
file.setAttribute("name", "campo1[]");
d.appendChild(file);
var file2 = document.createElement("input");
file2.setAttribute("type", "text");
file2.setAttribute("name", "campo2[]");
d.appendChild(file2);
document.getElementById("moreUploads").appendChild(d);
upload_number++;
}
</script>
<title>Untitled Document</title>
</head>
<body>
<p>
<select name="select[]" id="select[]">
<option value="fas">saf</option>
<option value="fdd">fsa</option>
</select>
<input name="campo1[]" type="text" id="campo1[]" />
<input name="campo2[]" type="text" id="campo2[]" />
<input type="button" name="button" id="button" value="Crear otra fila" onclick="addFileInput()"/>
</p>
<p> </p>
<div id="moreUploads"></div>
</body>
</html>