Edit in JSFiddle

Blob Demo by Troy Whorten 3/27/2014<br>
Enter whatever you want:<br>
<input id="val" type="text"/>
<button onclick="setBlob();">Set Blob</button>
<button onclick="document.getElementById('target').innerHTML=''; getBlob();">Get Blob</button>
<div id="target"></div>

//by Troy Whorten 3/27/2014
var blob = new Blob();

function write (str) {
    var doc = document.getElementById('target');
    var el = document.createElement('span');
    var br = document.createElement('br');
    el.innerHTML = str;
    el.style.color = "blue";
    doc.appendChild(el);
    doc.appendChild(br);
}

function setBlob () {
    var val = document.getElementById('val').value;
    blob = new Blob([val], {type : 'text/html'});
}

function getBlob() {
    var reader = new FileReader();
    reader.addEventListener("loadend", function() {
        write(reader.result);
    });
    reader.readAsText(blob);
}