Deleting Files & Records

Hello, I wanted to delete file on my server. I used the ulink(string completefilename) function but it gave fatal error saying that I was calling an undefined fuction. I was running my script on UNIX. Can someone plz tell me how to delete files on web server using php. Another thing which I wanted to ask is this when I have records resulting from the select query more than (lets suppose) 20 than I want to display them in different pages that is first 20 on one page and a link to next 20 and so on. What I do is while ( $rows = mysql_fetch_array($sqlResult) ) loop till first 20 records then break the loop but the problem is how to get next 20 records from the SQLResult when the user wants to view next 20 records that is in that page I have to ignore first 20 records but have to only pick next 20 records. How do I do that? Thanks in advance Regards Statbat