Viewport into the IE < 9


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


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:


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)