how to implement "pages" of results

Hi,

I'm sure this is a common question, so please forgive if it's been posted be
fore.

I have a select statement that selects records from a table:
"select * from $table where host='$somename'"

I then propagate a table with the returned data.  My goal is to only display
 30 records per "page", with links on each page that take the user to the ne
xt and previous 30 records.  I have played around with using "limit", but th
is seems to only get me the
next 30.  How to achieve the previous 30?  It would be easy if the records r
eturned were sequentially numbered...but, since I'm being selective in which
 records I return (host=$somename), this is not the case.  The first row may
 be 1, and the second row
may be 10, etc.

Anyone have any ideas on how to solve this?

Thanks!