New to PHP - Undefined variable: ??????

I'm new to PHP and can't get through my first script. I want to create a form that will allow the user to attach a file. I started with the file upload part of the form thinking that it ould give me the most problem, and it has. This is the error message that shows when I view the page in the browser: Warning: Undefined variable: File in D:\inetpub\thegospellady\www\kia\form.php on line 8 here is the url to the form: http://www.thegospellady.com/kia/form.php Please help. <?php /* This next conditional determines whether or not to handle the form, depending upon whether or not $File exists. */ if($File) { print ("File name: $File_name<P>\n"); print ("File size: $File_size<P>\n"); if(copy($File, "/users/$File_name")) { print ("Your file was successfully uploaded!<P>\n"); } else { print ("Your file could not be copied.<P>\n"); } unlink($File); } print ("Upload a file to the server:\n"); print ("<FORM ACTION=\"form.php\" METHOD=POST ENCTYPE=\"multipart/form-data\">\n"); print ("File <INPUT TYPE=FILE NAME=\"File\" SIZE=20><BR>\n"); print ("<INPUT TYPE=SUBMIT NAME=\"SUBMIT\" VALUE=\"Submit!\"></FORM>\n"); ?>