Five things:
- How to edit a post, the day after, if you found some errors you made?

- In the second line, put then next to each other must be put [b]them[/b] next to each other.

- Basicly: sin theta = lambda/d must be Basicly: sin theta = n.lambda/d where n is the order.

- I used SMF in front of the first jpg, as others did and my jpg was shown in the overview. Now it is gone. Why?

- I tried to ask this the board administrator because I didn't find it in Help, bud did not find how to reach the admin.