Did I not get enough sleep or what? This following code

var frame=document.getElementById(viewer);

frame.width=100;

frame.height=100;



var ctx=frame.getContext(2d);

var img=new Image();

img.src=http://www.ansearch.com/images/interface/item/small/image.png



img.onload=function() {

    // draw image

    ctx.drawImage(img, 0, 0)



    // Here's where the error happens:

    window.open(frame.toDataURL(image/png));

}

is throwing this error:

SECURITY_ERR: DOM Exception 18

There's no way this shouldn't work! Can anyone explain this, please?