Press button => choose pupil, hide all others

[jokris]

I have very little knowledge of VBA, wondering if you can help me with this.

Attached file contains a button top left corner.
When I click it, I would like to:
* Choose a pupil from a list of all pupils in column A
* Hide all other pupil rows
* Also, hide row 4
* When button is clicked again, show all hidden rows