Simple nested IF statement?

Hi there

have a column named code and against each code a value

I want to be able to enter a code then for the cell next to it to be assinged its linked value.

BUT if the Code is not in the range then i want the value WRONG to be displayed. How would i do this?

E.g.
Code Value
1 A
2 B
3 C

So if a person enters a valid code then a valid Value will be displayed