How to fetch the next 20 records from the database for the same search criteria?

How to fetch the next 20 records from the database for the same search
criteria?

I have a requirement to fetch 20 records at a time from the database(The
database contains atleast 100 records) when the user clicks on search
button. When the user clicks the next page button, the next 20 records
should be fetched for the same search criteria.How can i implement that in
my asp.net application?
Please help.