Get Selection Text

<script src="http://code.jquery.com/jquery-latest.js"></script>

<script language=javascript>
function getSelectionText() {
    var text = "";
    if (window.getSelection) {
        text = window.getSelection().toString();
    } else if (document.selection && document.selection.type != "Control") {
        text = document.selection.createRange().text;
    }
    return text;
}

</script>
<input type="text" value="Some text" id="txtInput" />
<div></div>
<script>
$("#txtInput").bind("mouseup", function(){
  $("div").text( getSelectionText() );
});
</script>