[cd34]

HTML:

<form method="post" enctype="multipart/form-data">
<input name="uploadedfile" type="file">
<input type="submit" name="submit" value="Upload">
</form>

Some php code to deal with the input:

    if (!(file_exists($_FILES['uploadedfile']['tmp_name']))) {
      $error .= "Please try again, I didn't get a file. ";
    } else {
       // do something with the file
    }