I have 20 fixed rows. The user inputs values in the cells in column A
and B through forms. The values should be shown in the order they've
been entered.

I have this information at first:

Column A | Column B
A | A1
C | C1
B | B1

If the user enters a new row with the value C2 it should be shown like
this:

Column A | Column B
A | A1
C | C1
C | C2
B | B1

How can I make this work?

Regards,

S