Simple input event polyfill

gistfile1.js

// function
function onKeyDown(e){
  // [input|textarea] trigger input with target.value // in case of input field, textarea
  // [contenteditable] trigger input with textContent // in case of contentEditable ?
}

// detect support for input
if(!'oninput' in document.createElement("input")){
  // add polyfill in this case
}