Preserve the table header while scrolling table

Hi,

How do I preserve the table header (giving details of what column contains what data)-- I mean: |

v

-

Name I-number department

-

to stay on the screen, and have only my table as scrollable?

currently my table contains a lot of data and the second page on scroll comes with the problem of what each column on each row of data means.

Thanks,

Adi