var KEY = { D: 68, W: 87, A: 65, S:83, RIGHT:39, UP:38, LEFT:37, DOWN:40, Q:81 };
  var input = {
          right: false,
          up: false,
          left: false,
          down: false,
          quit: false
  };
  
  function press(evt) {
          var code = evt.keyCode;
          switch(code) {
                  case KEY.RIGHT:
                  case KEY.D: input.right = true; break;
                  
                  case KEY.UP:
                  case KEY.W: input.up = true; break;
                  
                  case KEY.LEFT:
                  case KEY.A: input.left = true; break;
                  
                  case KEY.DOWN: 
                  case KEY.S: input.down = true; break;
                  
                  case KEY.Q: input.quit = true; break;
          }
  }
  
  function release(evt) {
          var code = evt.keyCode;
          switch(code) {
                  case KEY.RIGHT:
                  case KEY.D: input.right = false; break;
                  
                  case KEY.UP:
                  case KEY.W: input.up = false; break;
                  
                  case KEY.LEFT:
                  case KEY.A: input.left = false; break;
                  
                  case KEY.DOWN:
                  case KEY.S: input.down = false; break;
                  
                  case KEY.Q: break;
                  
                  default: trace('unrecognized key code: ' +code); break;
          }
  }