IF Command in the Rules help

[satay2hot]

I am a newbie and if anyone can help me if would be appreciated.
I have a cube called costing with 2 dimension  with product dimension and a measure dimension cogs_measure.
Inside the cogs_measure there is a picklist called "currency" like JPY USD etc.
I want the a field "Cur in JPY" to pick up "Cur FOB" field content if currency is "JPY"
I tried using this script
['COGS_measure':{'Cur in JPY'}]=N: if ( ['Currency'] = 'JPY' , ['Cur FOB'] , 0);

but it doesnt work. What is the right syntax?
Thank you so much for your help

Cheers
Vince