Edit Exchange Rate

[Michael Fellows]

Is the menu item "Actions/Edit Exchange Rate" implemented in a register windows?

I entered a transaction in one account denominated in THB,
against a USD denominated account.
Got a popup asking the exchange rate.
Filled it in and completed the transaction.
Then realized I entered THB/USD rather than USD/THB.
Went to "Actions" menu and selected "Edit Exchange Rate" and nothing happened.
Is that menu item not yet implemented perhaps?

I am using gnucash 1.8.8 on OS X 10.3.2