Invoice currency field grayed out

Invoice currency field grayed out:

I created a multi org with 2 OUs one in the US and the other in India. The currencies are USD and INR respectively. While keying in an invoice, the invoice currency tab is greyed out and only one currency is automatically picked and is not letting me change???

Soulution:

Go to Currency tab in Payable options and enable the check box, multiple currencies. Give the realised gain and relaised loss account and the rounding differences account.

And your problem is solved :)