Incarcare imagine in acelasi fisier php

Cum pot face acest "artificiu" sa am un fisier php in care sa am si partea fisierului .html in cel .php? scriptul meu pentru a incarca o imagine contine un fisier .html:

<form method="post" action="add.php" enctype="multipart/form-data">
File <input type="file" name="image">
<input TYPE="submit" name="upload" title="Add data to the Database" value="send"/>
</form>

si un fisier add.php:

function is_valid_type($file)
{
$valid_types = array("image/jpg", "image/jpeg", "image/bmp", "image/gif", "image/png");
if (in_array($file['type'], $valid_types))
return 1;
return 0;
}
$TARGET_PATH = "upload/";
$image = $_FILES['image'];
$image['name'] = mysql_real_escape_string($image['name']);
if ($image['name'] == "" )
{
$_SESSION['error'] = "All fields are required";
echo "All fields are required";
exit;
}
if (!is_valid_type($image))
{
$_SESSION['error'] = "You must upload a jpeg, gif, or bmp";
echo"You must upload a jpeg, gif, png or bmp";
exit;
}
if (file_exists($TARGET_PATH))
{
$image['name']=time() . $image['name'];
$image['name']=str_replace(' ', '_', $image['name']);
echo $image['name'];
$TARGET_PATH .= $image['name'];
}
if (move_uploaded_file($image['tmp_name'], $TARGET_PATH))
{
$sql = "insert into photo_upload (photo_filename) values ('" . $image['name'] . "')";
$result = mysql_query($sql) or die ("Could not insert data into DB: " . mysql_error());
exit;
}else{
$_SESSION['error'] = "Could not upload file. Check read/write persmissions on the directory";
exit;
}

In acest fisier php vreau sa am si partea celui html. Stiu sa includ codul cu echo, dar ce scriu la "action=..." de la form ?

Combini fisierele in unul singur cu extensia .php iar la form, action lasi liber.