URL decoder

gistfile1.txt

<script>
  function decodeURL() {
    var uri_enc = document.getElementById("url").value;
    var uri_dec = decodeURIComponent(uri_enc);
    var text = document.getElementById("text");
    text.textContent = uri_dec;
  }
</script>

<input id="url">
<button onclick="decodeURL();">Decode</button>

<script>
  document.getElementById("url").focus();
</script>