Button Image doesn't appear.

I alread used below code for the button.
---------------------------------------------
var btn = new AW.UI.Button;
btn.setId("btnDel");
btn.setControlText("Delete");
btn.setControlSize(100, 20)
btn.setControlImage("cut");
btn.refresh();
---------------------------------------------

But button images doesn't appear with "Explorer" browser.
Please let me know how can I fix the problem.

http://www.activewidgets.com/ui.button/
http://www.activewidgets.com/javascript.forum.15876.1/how-can-i-add-other.html
http://www.activewidgets.com/grid.howto.cells/images.html