Displaying next ten items

I am wondering what the mySQL commands are to display the next 10 records / previous 10 records. I am wondering how you pass a variable through a PHP script so the script knows which next or previous 10 entries to display. (Especially since this is all variable driven) Would you do something like ?next=21 and ?previous=1 as part of the URL link to know where your query should begin? I do know the LIMIT = mySQL command to limit 10 items to be displayed. How do you tell when there aren't 10 more entries left to display? IE If there are 46 records in a table and you are displaying 40 to 46 you don't want to offer a link to display records 50 to 59. Ron