Viewport into the IE < 9

Hi,

I have a div “main” with a layout. I do it:

layout.cells(“c”).attachURL(url);

And this file contains a button. I press de button and I create a window, but inside of the layout’s cell. I want to create it, but outside of the layout’s cell.
I think this:

dhxWins.attachViewportTo(parent.document.getElementById(“main”));

It works in firefox and IE 9, but in IE 7 and IE 8 there is an error:

No se puede obtener valor de la propiedad ‘srcElement’: el objeto es nulo o está sin definir
dhtmlx.js, Línea 1204 Carácter 27

Attachment the file dhxmls.js
dhtmlx.rar (243 KB)