Element.extend(
{
    bgiframe: function(styles)
    {
        if (window.ie6)
        {
            if (!this.getElement('iframe.bgiframe'))
            {
                styles = styles || {}
                ;
				var ifsrc = $pick(styles.src, 'javascript:false');
				delete styles.src;
				var ifopac = $pick(styles.opacity, true);
                    delete styles.opacity;
				(new Element('iframe', 
                {
                    'class': 'bgiframe', frameborder: 0, tabindex:  - 1, src: ifsrc, styles: $merge(
                    {
                        top:  - this.getStyle('borderTopWidth').toInt(), left: 
                            - this.getStyle('borderLeftWidth').toInt(), width:
                            this.offsetWidth, height: this.offsetHeight
                    }
                    , styles, 
                    {
                        display: 'block', position: 'absolute', zIndex:  - 1,
                            filter: ifopac ? "Alpha(Opacity='0')" : ''
                    }
                    )
                }
                )).injectBefore(this.firstChild)
            }
        }
        return this
    }
});