Once you have deposit your funds into JOYSO smart contract, there should be ETH, JOY and other kinds of ERC20 tokens available on JOYSO for you to trade.
Once you sign and submit the transaction message, you permit JOYSO to match orders for you.
Note that if the total amount of your order exceeds your available asset, there will be a pop up message in red. There will also be a reminder if the price you insert are too off from the market price.
Your order will be placed at the "My Order" section, located at the lower-left corner if it doesn't have an immediate match