Please elaborate a bit what do you mean. When some change happens in the “input” element, either “change” or “input” get triggered and you can get your text via “target.value” property. If you create not a text input, but a checkbox, you might need to get the value via “checked” property (though having “target.checked” value would be handy, going to add this in our TODO list).
As for “submit” it won’t be of any help to you, as this event should be triggered when the entire form (not a single input element) gets “submited” (for example to send data to the server). In case of the single input you better use “keydown” event and check whether the “key” property” is equal to “Enter” (see Keyboard Controls snippet in the stock Puzzles library).