Wont fix it:
You will have to replace your $queryy assignment with this line:
$query = "SELECT TOP 1 product_name,product_desc, price FROM products WHERE product_code='$product_code' LIMIT " . $Page_Start .
"," . $Per_Page;
Haven't tested this on your code, can you post the result if its not fixing your Problem? Also think of MySQL's
LIMIT _start_,_length_
to be used for the advised purpose of a pagination.
Edit:
Sorry overread SQL Server
Fix for SQL Server:
Replace $query
assignment with this:
$query = "SELECT TOP 1 product_name,product_desc, price FROM products WHERE product_code='$product_code'
AND product_id BETWEEN ($Page_Start) AND ($Page_Start + $Per_Page)";