Edit in JSFiddle

<div id="text">I am some text, select me and I will show you what you have selected.</div>
<div id="status"></div>

$('#text').on('mouseup', function(ev) {
    var selection = $(this).selection(),
        text = $(this).text().substring(selection.start, selection.end);
    $('#status').html('Selected from ' + selection.start +
                      " to " + selection.end +
                      ":<br /><span>" + text + "</span>");
});

$('#text').selection(8, 12).trigger('mouseup');

body{ 
    font-family: Helvetica,"Lucida Grande","Lucida Sans",Arial,Helvetica,sans-serif;
}

#text {
    padding: 5px;
    background-color: #FFFF66;
}

#status {
    padding: 10px;
}

#status span {
    font-weight: bold;
    color: #505050;
}