Código PHP:
<!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>
<script>
function agregaFila( id ) {
var tabla = document.getElementById( id );
var tbody = document.getElementById( tabla.id ).tBodies[0];
var row = tbody.rows[0] .cloneNode( true );
var id = 1;
while( document.getElementById( tabla.id+'_fila_'+id ) ) {
id++;
}
if (id<=3){
row.id = tabla.id+'_fila_'+id;
row.style.display = '';
tbody.appendChild( row );
}
}
function borraFila( fila ) {
var id = fila.id;
if( fila.parentNode.rows.length <= 2 ) return;
document.getElementById( id ).parentNode.removeChild( document.getElementById(id) );
}
</script>
</head>
<body>
<form enctype="multipart/form-data" action="subir.php" method="POST">
<select size="1" name="admin[]">
<option value="Male">Masculino</option>
<option value="Feme">Femenino</option>
</select><br>
<table id="tabla_1" >
<tbody>
</tr>
<tr>
<td><input type="file" name="pix1" size="60"> </td>
<td><a href="#" onClick="borraFila(this.parentNode.parentNode)">Eliminar</a></td>
</tr>
<tr id="tabla_1_fila_1" >
<td><input type="file" name="pix1" size="60"> </td>
<td> </td>
</tr>
</tbody>
<tr>
<td ><a href="javascript:agregaFila( 'tabla_1' );">Agregar Fila</a></td>
</tr>
</table>
<p><input type="submit" name="Upload" value="Aceptar">
</form>
</body>
</html>
<?php
include "coneccion.php";
$admin = @$_POST["admin"];
for ($i=0;$i<count($admin);$i++){
$admi = $admin[$i];
}
if(isset($_POST['Upload'])){
$nombre1 = $_FILES['pix1']['name'];
$nombre2 = $_FILES['pix2']['name'];
$nombre3 = $_FILES['pix3']['name'];
$img1="./imagenes/".$nombre1.$_FILES['pix']['name'];
$img1_tmp = $_FILES["pix"]["tmp_name"];
move_uploaded_file($img1_tmp,$img1);
$img2="./imagenes/".$nombre2.$_FILES['pix']['name'];
$img2_tmp = $_FILES["pix"]["tmp_name"];
move_uploaded_file($img2_tmp,$img2);
$img3="./imagenes/".$nombre3.$_FILES['pix']['name'];
$img3_tmp = $_FILES["pix"]["tmp_name"];
move_uploaded_file($img3_tmp,$img3);
//echo "<p><b>El archivo se ha cargado satisfactoriamente:</b>{$_FILES['pix']['name']}({$_FILES['pix']['size']})</p>";
$query = "INSERT INTO articulos (fecha_upl, original_upl, id_admin) VALUES ( NOW(), '".$nombre1."' , '".$nombre2."', '".$nombre3."', '".$admi."')";
mysql_query($query);
}
?> 
