function onImage(args, kwargs){
   // append message to previous ones, then scroll so latest is at
    // the bottom. Send 'cls' kwarg to modify the output class.
    var mwin = $("#messagewindow");
    mwin.append("<img src='" + args[0]+"'>" + "</img></br>"+args[1]);
    mwin.animate({
        scrollTop: document.getElementById("messagewindow").scrollHeight + 500
    }, 0);


    }