button image only no title

I tried with this code but does not work:

var dx = Ti.UI.createButton({
    backgroundImage: '/images/dx.png',
        height: 16,
        width: 16,
    });
    win1.rightNavButton = dx;

But if I put this code, is obviously only see the button with the title:

var dx = Ti.UI.createButton({
    title:'Image',
        height: 16,
        width: 16,
    });
    win1.rightNavButton = dx;

how can I make it work? Thank you!

You can use a imageview as a button with a click event attached.

Try with "image" property.

http://img145.imageshack.us/img145/9373/dxbutton.png has the border as if it were a button .. how can I remove it?