Read File Upload Date With JS?

I have a form like this:

Code:

<input type="text" id="forename" />
<input type="text" id="surname" />
<input type="file" id="myfile" />

The first two fields obviously contain text data, and the last is a file upload field.I can get the values of the first two fields in JavaScript easily by using:

Code:

var forename = document.getElementById("forename").value;
var surname = document.getElementById("forename").value;

But I don't have a clue how to get the contents of the file uploaded.

If I use:

Code:

var myfile = document.getElementById("myfile").value;

That simply returns the filename of the file, but I want the actual data in the file!Now I realise that the data probably isn't even accessed from the users hd until the form is submitted properly and sent to a server-side script (which I'm not doing), so I probably need a hackish method to make the browser send the contents to the JS function rather than as an extra 'package' to the server.