different currency in amount in words in purchase order form using live cycle designer

Dear Experts,

kindly help in getting the appropriate currency in amount in words in the purchase order form.

For ex. p.o currency is dollars, total amount is 200.50

and amount in words should be like two hundred dollars and fifty cents.

if another p.o currency is riyal, total amount 100.50

and amount in words should be like one hundred riyal and fifty baisa.

i have done amount in words using wordnum function.

please let me know how to get the appropriate currency in the amount in words, which it should fetch from p.o currency field.

Thanks & regards

Yogi