I was there May this year take the US dollar they love it plus with the current exchange rate your onto a winner,you cant get there Paso over here anyway as they dont allow it it leave there country so make sure you dont have any ammount left when you come home as you get Paso in change when you buy something
also take lots of 1 dollar bills for tips for the bagage handlers and porters at your hotel
there all want tips as its such a poor country