<?
    # this is our sexy routine

    function upload_a_file($field, $path){
        global $HTTP_POST_FILES;

        if ($HTTP_POST_FILES[$field]['name'] != ""){
            $src = $HTTP_POST_FILES[$field]['tmp_name'];
            if (is_uploaded_file($src)){
                $dest = trim($HTTP_POST_FILES[$field]['name']);
                $i=0;
                while(file_exists("$path/$dest")){
                    $dest = $i.'_'.trim($HTTP_POST_FILES[$field]['name']);
                    $i++;
                }
                copy($src,"$path/$dest");
                return $dest;
            }
        }
        return 0;
    }

    # see if a file has been uploaded
    $path = '/path/to/where/i/want/the/file';
    $file = upload_a_file('myfile',$path);

    if ($file){
        echo "a file has been uploaded here: $path/$file<br><br>";
    }

?>

<form method="post" enctype="multipart/form-data">
Upload a file:<br>
<input type="file" name="myfile"> <input type="submit">
</form>