Why are some of my keys not working?

I’m using onkeydown and event.key to get keyboard input in my javascript calculator. There seems to be a problem in my switch statement, making use of the results:

window.onkeydown = function(e) {
  var key = e.key;
  console.log("event.key: " + key);
  var keyID;
  switch(key) {
    case "%":
      keyID = "percent";
    case "Backspace":
      keyID = "c";
    case ".":
      keyID = "dot";
      keyID = key;
  $("#" + keyID).click();
  console.log("keyID: " + keyID);

Pretty much everything comes out of the first console.log line (“event.key”), but many keys don’t make it through the second one (“keyID”). "-" comes through, but "+" and "/" don’t. Since the first log is coming through, the problem must not be with onkeydown or .key, but with my code, but I can’t see what it is. Help?

(Full pen: http://codepen.io/AbdiViklas/pen/GjdrZQ?editors=1011)

(I apologize if this answer is short. Not in a position to give further details)

The event on keydown uses codes instead of the character associated with the key.

Thanks! I was dismayed by the difference in those codes between top-row and numpad numbers, and the lack of distinction between “=” and “+”, and was ready to use a combo of keydown and keypress, but the .key property seems like a nice way around all that: http://www.w3schools.com/jsref/event_key_key.asp

Okay, solved my own question: I had a bunch of html elements with ids like “+”, “=”, etc. “-” just happens to be about the only one that was a valid ID name for jQuery purposes.