var HtmlWindow = 
{		
	open: function(width, height) {
		windowsize = Html.getWindowsize();
		xpos = (windowsize[0] / 2) - (width / 2);
		ypos = (windowsize[1] / 2) - (height / 2) - 20 + document.documentElement.scrollTop;
		// position window
		win = document.getElementById('html_window');
		win.style.top = ypos + 'px';
		win.style.left = xpos + 'px';
		win.style.display = 'block';
	},
	
	close: function() {
		if (win = document.getElementById('html_window')) {
			win.style.display = 'none';
		}
		Html.hideBlocker();		
	}
}