I often want to trade a fixed amount of goods. Yet I feel bad when I have to declined several people from a trade.
Thus why I feel there should be a setting to allow you to select how many times you would like to a trade when you post a trade. Lets say you have 1100 water and want to trade 400 units twice (800 total) than you should be able to set it to 2 trades after you select amount you want to trade. And yes it would have red numbers if you try to do more than what you have. So if I select 400 waters and select 3 it will not allow me to do so.
Once you made your 2 trades of 400 units of water you are automatically removed for that trade same time limit for that trade.