Function casper_contract::contract_api::system::transfer_from_purse_to_purse

pub fn transfer_from_purse_to_purse(
    source: URef, 
    target: URef, 
    amount: U512, 
    id: Option<u64>
) -> Result<(), ApiError>

Transfers amount of motes from source purse to target purse. If target does not exist the transfer fails.