[O] table and a if structure

[Uwe Brauer]

Hi

I have the following table

| name   | value1 | value2 | result      |
|--------+--------+--------+-------------|
| first  | 4      |      5 | 4.2         |
| second | NP     |      5 | 0.8 NP + 1. |
#+TBLFM: $4=if("$2" == "NP",string("NP"),0.8*$2+0.2*$3)

The idea is if the second column has an entry NP then no operation
should be applied. But my table does not work. So it seems that there is
some syntax error.

Thanks

Uwe Brauer