You must select a file to upload -> Error :(

Thank those who e-mailed me back on my last question. Now, I am trying my 2nd project. I have attempted to write a script from a tutorial I found at "HotScripts" ... I am trying to upload an image from html form to apache. I chmod(ed) the directory on my Linux server and I have typed in the right path names ... BUT I am confused on why this isnt
working.

HTML FORM
---------

Uploading a File

PHP HANDLER
------------
<?

// name of the directory that your uploads will be kept in
$dirname = "images";

// the path that the uploads directory will be placed in
define(PATH, "/var/www/html/building/images/");

// gets just the file name and extension from the file input
// in the form
$filename = $myfile_name;

// check if they actually placed something in the file input
if ($filename != "")
{
// check if the directory exists
// if it doesnt exist, make the directory
if (!$dir = @opendir(PATH.$dirname))
// make the directory (sets chmod to 700)
mkdir(PATH.$dirname, 0700) or die("Error: could not
make directory.");

// copy the file from the temporary upload position to where
you want it
copy($myfile, PATH.$dirname."/".$filename) or
die("Error: could not copy file.");

// delete the temporary uploaded file
unlink($myfile) or die("Error: could not delete
uploaded file.");

// tell them it worked
echo "File uploaded successfully.";
}
else
{
// tell them to browse for a file
echo "You must select a file to upload.";
}

?>

I am still learning and I cant see why this tutorial code doesnt work when I try to run it. I keep getting the error message that says "You must select a file to upload." BUT -> I did select a file.

Seriously, any help would be welcomed
...

- Adam