Thank you very much for your help!!
I´ve been on vacation for some days so I haven´t been looking at the Forum during that time. I´m not very used to access but I want to learn much more about it because I have sampled lots of data from lakes which I want to write into an Access-database. I´ve done some progress but the database isn´t very good yet. I want to make forms for reading and inputs.
I´ve read some negative opinions about using LookUppwrds. Some call it even evil. How to do instead?
Since your answer I have now learned a little more about events, controls and buttons as you told me.
I hope for further progress.