I have a really good internet connection, which i want to make use of it by combining it with my 200 gig hard drive into a file hosting site.

The above task, i have no problem at all.

the problem is that, i need a simple upload system/script that does these following tasks:

1. basic function (upload the file to the given folder on server)

2. show link to the file as an id, example (download.php?id=512) OR show a greeting message saying, "File has been uploaded and your id is 512" and then, to download the file, they have to enter a unique id (examle 512) at the home page, where it says, pick up the file

3. weather they are given the link to the file or just the id number, i want them to be taken to the downloading page where they either wait few seconds before download starts or where they see ads on a page where download of the file begins

anyone help me plz

Have a look at www.php.net for information on how to do this in php.
1. File uploads in php: http://ca.php.net/features.file-upload
2. Very standard php code
3. Standard HTML (put on the page with ads: this will start a download after the page is loaded):