<input type="file" id="files" name="files" />
<p>
<div id="FIN"></div>

<script>
// just use it with text files
var reader = new FileReader();

// it gets called when the FileReader is done reading.
reader.onload = function(e) {
      document.getElementById("FIN").innerHTML = reader.result;
}

// it gets called when a file is selected
function handleFileSelect(evt) {
      var files = evt.target.files; // FileList object
      reader.readAsText(files[0]);
}

// configure callback function for changes on file selector
document.getElementById('files').addEventListener('change', handleFileSelect, false);

</script>